393931644 has 24 divisors (see below), whose sum is σ = 923798400. Its totient is φ = 130649904.

The previous prime is 393931619. The next prime is 393931651. The reversal of 393931644 is 446139393.

It is a junction number, because it is equal to n+sod(n) for n = 393931596 and 393931605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80094 + ... + 84869.

It is an arithmetic number, because the mean of its divisors is an integer number (38491600).

Almost surely, 2^393931644 is an apocalyptic number.

It is an amenable number.

393931644 is an abundant number, since it is smaller than the sum of its proper divisors (529866756).

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

393931644 is a wasteful number, since it uses less digits than its factorization.

393931644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165169 (or 165167 counting only the distinct ones).

The product of its digits is 209952, while the sum is 42.

The square root of 393931644 is about 19847.7113038254. The cubic root of 393931644 is about 733.0612945969.

The spelling of 393931644 in words is "three hundred ninety-three million, nine hundred thirty-one thousand, six hundred forty-four".