400312631 has 4 divisors (see below), whose sum is σ = 417717552. Its totient is φ = 382907712.

The previous prime is 400312589. The next prime is 400312639. The reversal of 400312631 is 136213004.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 400312631 - 2⁶ = 400312567 is a prime.

It is a super-2 number, since 2×400312631² = 320500405076284322, 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 (400312639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8702426 + ... + 8702471.

It is an arithmetic number, because the mean of its divisors is an integer number (104429388).

Almost surely, 2^400312631 is an apocalyptic number.

400312631 is a deficient number, since it is larger than the sum of its proper divisors (17404921).

400312631 is a wasteful number, since it uses less digits than its factorization.

400312631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17404920.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 400312631 is about 20007.8142484380. The cubic root of 400312631 is about 736.9982068152.

Adding to 400312631 its reverse (136213004), we get a palindrome (536525635).

The spelling of 400312631 in words is "four hundred million, three hundred twelve thousand, six hundred thirty-one".