639905042502 has 48 divisors (see below), whose sum is σ = 1538138496960. Its totient is φ = 190623994800.

The previous prime is 639905042477. The next prime is 639905042507. The reversal of 639905042502 is 205240509936.

639905042502 is a `hidden beast` number, since 6 + 3 + 9 + 90 + 50 + 4 + 2 + 502 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639905042507) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27376824 + ... + 27400187.

It is an arithmetic number, because the mean of its divisors is an integer number (32044552020).

Almost surely, 2^639905042502 is an apocalyptic number.

639905042502 is an abundant number, since it is smaller than the sum of its proper divisors (898233454458).

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

639905042502 is a wasteful number, since it uses less digits than its factorization.

639905042502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54777089 (or 54777086 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 45.

The spelling of 639905042502 in words is "six hundred thirty-nine billion, nine hundred five million, forty-two thousand, five hundred two".