399466656 has 36 divisors (see below), whose sum is σ = 1135984122. Its totient is φ = 133155456.

The previous prime is 399466609. The next prime is 399466667. The reversal of 399466656 is 656664993.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 399200400 + 266256 = 19980^2 + 516^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 693231 + ... + 693806.

Almost surely, 2^399466656 is an apocalyptic number.

399466656 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

399466656 is an abundant number, since it is smaller than the sum of its proper divisors (736517466).

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

399466656 is a wasteful number, since it uses less digits than its factorization.

399466656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387053 (or 1387042 counting only the distinct ones).

The product of its digits is 6298560, while the sum is 54.

The square root of 399466656 is about 19986.6619524122. The cubic root of 399466656 is about 736.4786780564.

The spelling of 399466656 in words is "three hundred ninety-nine million, four hundred sixty-six thousand, six hundred fifty-six".