399664524 has 72 divisors (see below), whose sum is σ = 1101483264. Its totient is φ = 110484000.

The previous prime is 399664481. The next prime is 399664553. The reversal of 399664524 is 425466993.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78249 + ... + 83199.

Almost surely, 2^399664524 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399664524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (550741632).

399664524 is an abundant number, since it is smaller than the sum of its proper divisors (701818740).

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

399664524 is a wasteful number, since it uses less digits than its factorization.

399664524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5027 (or 4994 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 48.

The square root of 399664524 is about 19991.6113407599. The cubic root of 399664524 is about 736.6002580905.

The spelling of 399664524 in words is "three hundred ninety-nine million, six hundred sixty-four thousand, five hundred twenty-four".