3931243577820 has 72 divisors (see below), whose sum is σ = 12842062361856. Its totient is φ = 967690726272.

The previous prime is 3931243577803. The next prime is 3931243577843. The reversal of 3931243577820 is 287753421393.

It is a happy number.

3931243577820 is a `hidden beast` number, since 3 + 9 + 3 + 1 + 2 + 43 + 577 + 8 + 20 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 840006972 + ... + 840011651.

It is an arithmetic number, because the mean of its divisors is an integer number (178361977248).

Almost surely, 2^{3931243577820} is an apocalyptic number.

3931243577820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3931243577820 is an abundant number, since it is smaller than the sum of its proper divisors (8910818784036).

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

3931243577820 is a wasteful number, since it uses less digits than its factorization.

3931243577820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1680018651 (or 1680018646 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 54.

The spelling of 3931243577820 in words is "three trillion, nine hundred thirty-one billion, two hundred forty-three million, five hundred seventy-seven thousand, eight hundred twenty".