31211113131 has 128 divisors (see below), whose sum is σ = 53508833280. Its totient is φ = 17806089600.

The previous prime is 31211113121. The next prime is 31211113159. The reversal of 31211113131 is 13131111213.

It is a de Polignac number, because none of the positive numbers 2^k-31211113131 is a prime.

It is a super-2 number, since 2×31211113131² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31211113111) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 81490966 + ... + 81491348.

It is an arithmetic number, because the mean of its divisors is an integer number (418037760).

Almost surely, 2^31211113131 is an apocalyptic number.

31211113131 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

31211113131 is a deficient number, since it is larger than the sum of its proper divisors (22297720149).

31211113131 is a wasteful number, since it uses less digits than its factorization.

31211113131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 654 (or 648 counting only the distinct ones).

The product of its digits is 54, while the sum is 18.

Adding to 31211113131 its reverse (13131111213), we get a palindrome (44342224344).

The spelling of 31211113131 in words is "thirty-one billion, two hundred eleven million, one hundred thirteen thousand, one hundred thirty-one".