639929255420 has 96 divisors (see below), whose sum is σ = 1694311952256. Its totient is φ = 197587353600.

The previous prime is 639929255419. The next prime is 639929255437. The reversal of 639929255420 is 24552929936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4213301 + ... + 4362540.

It is an arithmetic number, because the mean of its divisors is an integer number (17649082836).

Almost surely, 2^639929255420 is an apocalyptic number.

It is an amenable number.

639929255420 is an abundant number, since it is smaller than the sum of its proper divisors (1054382696836).

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

639929255420 is a wasteful number, since it uses less digits than its factorization.

639929255420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8575911 (or 8575909 counting only the distinct ones).

The product of its (nonzero) digits is 10497600, while the sum is 56.

The spelling of 639929255420 in words is "six hundred thirty-nine billion, nine hundred twenty-nine million, two hundred fifty-five thousand, four hundred twenty".