31540631 has 2 divisors, whose sum is σ = 31540632. Its totient is φ = 31540630.

The previous prime is 31540573. The next prime is 31540637. The reversal of 31540631 is 13604513.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31540631 is a prime.

It is a super-2 number, since 2×31540631² = 1989622807756322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31540597 and 31540606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31540637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770315 + 15770316.

It is an arithmetic number, because the mean of its divisors is an integer number (15770316).

Almost surely, 2^31540631 is an apocalyptic number.

31540631 is a deficient number, since it is larger than the sum of its proper divisors (1).

31540631 is an equidigital number, since it uses as much as digits as its factorization.

31540631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 31540631 is about 5616.1046108491. The cubic root of 31540631 is about 315.9537099048.

The spelling of 31540631 in words is "thirty-one million, five hundred forty thousand, six hundred thirty-one".