400331631 has 64 divisors (see below), whose sum is σ = 655257600. Its totient is φ = 212599296.

The previous prime is 400331621. The next prime is 400331669. The reversal of 400331631 is 136133004.

It is not a de Polignac number, because 400331631 - 2⁵ = 400331599 is a prime.

It is a super-2 number, since 2×400331631² = 320530829558240322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 400331598 and 400331607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400331611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2549805 + ... + 2549961.

It is an arithmetic number, because the mean of its divisors is an integer number (10238400).

Almost surely, 2^400331631 is an apocalyptic number.

400331631 is a deficient number, since it is larger than the sum of its proper divisors (254925969).

400331631 is a wasteful number, since it uses less digits than its factorization.

400331631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 400331631 is about 20008.2890572882. The cubic root of 400331631 is about 737.0098666558.

Adding to 400331631 its reverse (136133004), we get a palindrome (536464635).

The spelling of 400331631 in words is "four hundred million, three hundred thirty-one thousand, six hundred thirty-one".