399021864 has 32 divisors (see below), whose sum is σ = 999108000. Its totient is φ = 132800192.

The previous prime is 399021829. The next prime is 399021877. The reversal of 399021864 is 468120993.

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, 3202 + ... + 28430.

It is an arithmetic number, because the mean of its divisors is an integer number (31222125).

Almost surely, 2^399021864 is an apocalyptic number.

It is an amenable number.

399021864 is an abundant number, since it is smaller than the sum of its proper divisors (600086136).

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

399021864 is a wasteful number, since it uses less digits than its factorization.

399021864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25897 (or 25893 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 399021864 is about 19975.5316324748. The cubic root of 399021864 is about 736.2052288817.

The spelling of 399021864 in words is "three hundred ninety-nine million, twenty-one thousand, eight hundred sixty-four".