639943734810 has 32 divisors (see below), whose sum is σ = 1540215881280. Its totient is φ = 170168227328.

The previous prime is 639943734799. The next prime is 639943734817. The reversal of 639943734810 is 18437349936.

It is a super-2 number, since 2×639943734810² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (639943734817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30203940 + ... + 30225119.

It is an arithmetic number, because the mean of its divisors is an integer number (48131746290).

Almost surely, 2^639943734810 is an apocalyptic number.

639943734810 is an abundant number, since it is smaller than the sum of its proper divisors (900272146470).

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

639943734810 is a wasteful number, since it uses less digits than its factorization.

639943734810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60429422.

The product of its (nonzero) digits is 11757312, while the sum is 57.

The spelling of 639943734810 in words is "six hundred thirty-nine billion, nine hundred forty-three million, seven hundred thirty-four thousand, eight hundred ten".