639310836 has 12 divisors (see below), whose sum is σ = 1491725312. Its totient is φ = 213103608.

The previous prime is 639310811. The next prime is 639310849. The reversal of 639310836 is 638013936.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 639310794 and 639310803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26637940 + ... + 26637963.

Almost surely, 2^639310836 is an apocalyptic number.

It is an amenable number.

639310836 is an abundant number, since it is smaller than the sum of its proper divisors (852414476).

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

639310836 is a wasteful number, since it uses less digits than its factorization.

639310836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53275910 (or 53275908 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 639310836 is about 25284.5968130797. The cubic root of 639310836 is about 861.4644401614.

It can be divided in two parts, 639310 and 836, that added together give a triangular number (640146 = T₁₁₃₁).

The spelling of 639310836 in words is "six hundred thirty-nine million, three hundred ten thousand, eight hundred thirty-six".