639731961502 has 32 divisors (see below), whose sum is σ = 974536843392. Its totient is φ = 314915144544.

The previous prime is 639731961469. The next prime is 639731961523. The reversal of 639731961502 is 205169137936.

It is a self number, because there is not a number n which added to its sum of digits gives 639731961502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58380208 + ... + 58391164.

It is an arithmetic number, because the mean of its divisors is an integer number (30454276356).

Almost surely, 2^639731961502 is an apocalyptic number.

639731961502 is a deficient number, since it is larger than the sum of its proper divisors (334804881890).

639731961502 is a wasteful number, since it uses less digits than its factorization.

639731961502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12232.

The product of its (nonzero) digits is 1837080, while the sum is 52.

The spelling of 639731961502 in words is "six hundred thirty-nine billion, seven hundred thirty-one million, nine hundred sixty-one thousand, five hundred two".