639974776 has 16 divisors (see below), whose sum is σ = 1371374640. Its totient is φ = 274274880.

The previous prime is 639974771. The next prime is 639974789. The reversal of 639974776 is 677479936.

639974776 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 639974776.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639974771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5714005 + ... + 5714116.

It is an arithmetic number, because the mean of its divisors is an integer number (85710915).

Almost surely, 2^639974776 is an apocalyptic number.

It is an amenable number.

639974776 is an abundant number, since it is smaller than the sum of its proper divisors (731399864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639974776 is a wasteful number, since it uses less digits than its factorization.

639974776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11428134 (or 11428130 counting only the distinct ones).

The product of its digits is 12002256, while the sum is 58.

The square root of 639974776 is about 25297.7227433617. The cubic root of 639974776 is about 861.7625543097.

The spelling of 639974776 in words is "six hundred thirty-nine million, nine hundred seventy-four thousand, seven hundred seventy-six".