31213023631 has 2 divisors, whose sum is σ = 31213023632. Its totient is φ = 31213023630.

The previous prime is 31213023617. The next prime is 31213023671. The reversal of 31213023631 is 13632031213.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31213023631 - 2²³ = 31204635023 is a prime.

It is a super-2 number, since 2×31213023631² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31213023596 and 31213023605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31213023671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606511815 + 15606511816.

It is an arithmetic number, because the mean of its divisors is an integer number (15606511816).

Almost surely, 2^31213023631 is an apocalyptic number.

31213023631 is a deficient number, since it is larger than the sum of its proper divisors (1).

31213023631 is an equidigital number, since it uses as much as digits as its factorization.

31213023631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 25.

Adding to 31213023631 its reverse (13632031213), we get a palindrome (44845054844).

The spelling of 31213023631 in words is "thirty-one billion, two hundred thirteen million, twenty-three thousand, six hundred thirty-one".