perfect number

n. A positive integer that is equal to the sum of its positive integral factors, including 1 but excluding itself.

perfect number

n (Mathematics) an integer, such as 28, that is equal to the sum of all its possible factors, excluding itself

per′fect num′ber

n. a positive number that is equal to the sum of all positive integers that are submultiples of it, as 6, which is equal to the sum of 1, 2, and 3. [1350–1400]

per·fect number

(pûr′fĭkt) A positive integer that equals the sum of all of its divisors other than itself. An example is 28, whose divisors (not counting itself) are 1, 2, 4, 7, and 14, which added together give 28.

Perfect Number

perfect number

[′pər·fikt ′nəm·bər] (mathematics) An integer which equals the sum of all its factors other than itself.

Perfect Number

a positive integer that is equal to the sum of all its factors except itself. Examples of perfect numbers are 6 = 1 + 2 + 3 and 28 = 1 + 2 + 4 + 7 + 14.

As early as the third century B.C., Euclid showed that even perfect numbers could be obtained from the formula 2p^–l(2p – 1) when p and 2p – 1 are prime numbers. Approximately 20 even perfect numbers have been found in this way. As of 1976, no odd perfect numbers are known, and their existence remains an open question. Perfect numbers were first investigated by the Pythagoreans, who ascribed a special mystical meaning to such numbers and combinations of such numbers.

perfect number

equal in value to the sum of those natural numbers that are less than the given number but that also divide (with zero remainder) the given number. [Math.: EB, VII: 872]See: Perfection

单词	perfect number
释义	perfect number perfect number n. A positive integer that is equal to the sum of its positive integral factors, including 1 but excluding itself. perfect number n (Mathematics) an integer, such as 28, that is equal to the sum of all its possible factors, excluding itself per′fect num′ber n. a positive number that is equal to the sum of all positive integers that are submultiples of it, as 6, which is equal to the sum of 1, 2, and 3. [1350–1400] per·fect number (pûr′fĭkt) A positive integer that equals the sum of all of its divisors other than itself. An example is 28, whose divisors (not counting itself) are 1, 2, 4, 7, and 14, which added together give 28. Perfect Number perfect number [′pər·fikt ′nəm·bər] (mathematics) An integer which equals the sum of all its factors other than itself. Perfect Number a positive integer that is equal to the sum of all its factors except itself. Examples of perfect numbers are 6 = 1 + 2 + 3 and 28 = 1 + 2 + 4 + 7 + 14. As early as the third century B.C., Euclid showed that even perfect numbers could be obtained from the formula 2p^–l(2p – 1) when p and 2p – 1 are prime numbers. Approximately 20 even perfect numbers have been found in this way. As of 1976, no odd perfect numbers are known, and their existence remains an open question. Perfect numbers were first investigated by the Pythagoreans, who ascribed a special mystical meaning to such numbers and combinations of such numbers. perfect number equal in value to the sum of those natural numbers that are less than the given number but that also divide (with zero remainder) the given number. [Math.: EB, VII: 872]See: Perfection
随便看	möle mölle möller scattering ophthalmic nerve ophthalmic nerve cn v1 ophthalmic nursing diploma ophthalmic ointment ophthalmic optician ophthalmic photographers' society ophthalmic qualification committee ophthalmic reaction ophthalmic region ophthalmic research network ophthalmic scoliosis ophthalmic solution ophthalmic solutions ophthalmic sonographer ophthalmic speculum ophthalmic stain ophthalmic surgeon ophthalmic surgery ophthalmic surgery, lasers and imaging ophthalmic vein ophthalmic vein, inferior ophthalmic veins