31130213231 has 4 divisors (see below), whose sum is σ = 33524845032. Its totient is φ = 28735581432.

The previous prime is 31130213209. The next prime is 31130213249. The reversal of 31130213231 is 13231203113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13231203113 = 601 ⋅22015313.

It is a cyclic number.

It is not a de Polignac number, because 31130213231 - 2²² = 31126018927 is a prime.

It is a super-2 number, since 2×31130213231² (a number of 22 digits) 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 (31130263231) 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, 1197315881 + ... + 1197315906.

It is an arithmetic number, because the mean of its divisors is an integer number (8381211258).

Almost surely, 2^31130213231 is an apocalyptic number.

31130213231 is a deficient number, since it is larger than the sum of its proper divisors (2394631801).

31130213231 is a wasteful number, since it uses less digits than its factorization.

31130213231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2394631800.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31130213231 its reverse (13231203113), we get a palindrome (44361416344).

The spelling of 31130213231 in words is "thirty-one billion, one hundred thirty million, two hundred thirteen thousand, two hundred thirty-one".