400404631 has 16 divisors (see below), whose sum is σ = 456542208. Its totient is φ = 347608800.

The previous prime is 400404623. The next prime is 400404643. The reversal of 400404631 is 136404004.

It is a happy number.

It is not a de Polignac number, because 400404631 - 2³ = 400404623 is a prime.

It is a super-2 number, since 2×400404631² = 320647737052492322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400404601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 249925 + ... + 251521.

It is an arithmetic number, because the mean of its divisors is an integer number (28533888).

Almost surely, 2^400404631 is an apocalyptic number.

400404631 is a deficient number, since it is larger than the sum of its proper divisors (56137577).

400404631 is a wasteful number, since it uses less digits than its factorization.

400404631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2622.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 400404631 is about 20010.1132180705. The cubic root of 400404631 is about 737.0546615594.

Adding to 400404631 its reverse (136404004), we get a palindrome (536808635).

The spelling of 400404631 in words is "four hundred million, four hundred four thousand, six hundred thirty-one".