639243255 has 32 divisors (see below), whose sum is σ = 1219728384. Its totient is φ = 279518976.

The previous prime is 639243179. The next prime is 639243257. The reversal of 639243255 is 552342936.

It is not a de Polignac number, because 639243255 - 2⁸ = 639242999 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639243257) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 129934 + ... + 134763.

It is an arithmetic number, because the mean of its divisors is an integer number (38116512).

Almost surely, 2^639243255 is an apocalyptic number.

639243255 is a deficient number, since it is larger than the sum of its proper divisors (580485129).

639243255 is a wasteful number, since it uses less digits than its factorization.

639243255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264735.

The product of its digits is 194400, while the sum is 39.

The square root of 639243255 is about 25283.2603712417. The cubic root of 639243255 is about 861.4340842028.

The spelling of 639243255 in words is "six hundred thirty-nine million, two hundred forty-three thousand, two hundred fifty-five".