31511231023 has 4 divisors (see below), whose sum is σ = 31523624928. Its totient is φ = 31498837120.

The previous prime is 31511231009. The next prime is 31511231039. The reversal of 31511231023 is 32013211513.

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 31511231023 - 2²⁵ = 31477676591 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31511230985 and 31511231003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31511231083) 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, 6193138 + ... + 6198223.

It is an arithmetic number, because the mean of its divisors is an integer number (7880906232).

Almost surely, 2^31511231023 is an apocalyptic number.

31511231023 is a deficient number, since it is larger than the sum of its proper divisors (12393905).

31511231023 is a wasteful number, since it uses less digits than its factorization.

31511231023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12393904.

The product of its (nonzero) digits is 540, while the sum is 22.

Adding to 31511231023 its reverse (32013211513), we get a palindrome (63524442536).

The spelling of 31511231023 in words is "thirty-one billion, five hundred eleven million, two hundred thirty-one thousand, twenty-three".