31540320431 has 4 divisors (see below), whose sum is σ = 31541004264. Its totient is φ = 31539636600.

The previous prime is 31540320401. The next prime is 31540320433. The reversal of 31540320431 is 13402304513.

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 31540320431 - 2³⁰ = 30466578607 is a prime.

It is a super-2 number, since 2×31540320431² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31540320431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31540320433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267305 + ... + 366786.

It is an arithmetic number, because the mean of its divisors is an integer number (7885251066).

Almost surely, 2^31540320431 is an apocalyptic number.

31540320431 is a deficient number, since it is larger than the sum of its proper divisors (683833).

31540320431 is an equidigital number, since it uses as much as digits as its factorization.

31540320431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683832.

The product of its (nonzero) digits is 4320, while the sum is 26.

Adding to 31540320431 its reverse (13402304513), we get a palindrome (44942624944).

The spelling of 31540320431 in words is "thirty-one billion, five hundred forty million, three hundred twenty thousand, four hundred thirty-one".