399904990 has 16 divisors (see below), whose sum is σ = 722976480. Its totient is φ = 159262560.

The previous prime is 399904987. The next prime is 399905017. The reversal of 399904990 is 99409993.

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, 85026 + ... + 89605.

It is an arithmetic number, because the mean of its divisors is an integer number (45186030).

Almost surely, 2^399904990 is an apocalyptic number.

399904990 is a deficient number, since it is larger than the sum of its proper divisors (323071490).

399904990 is a wasteful number, since it uses less digits than its factorization.

399904990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174867.

The product of its (nonzero) digits is 708588, while the sum is 52.

The square root of 399904990 is about 19997.6246089379. The cubic root of 399904990 is about 736.7479584699.

The spelling of 399904990 in words is "three hundred ninety-nine million, nine hundred four thousand, nine hundred ninety".