31131121311 has 40 divisors (see below), whose sum is σ = 49754764400. Its totient is φ = 19339378560.

The previous prime is 31131121279. The next prime is 31131121367. The reversal of 31131121311 is 11312113113.

31131121311 is a `hidden beast` number, since 311 + 31 + 12 + 1 + 311 = 666.

It is not a de Polignac number, because 31131121311 - 2⁵ = 31131121279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31131121211) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 71926 + ... + 259683.

It is an arithmetic number, because the mean of its divisors is an integer number (1243869110).

Almost surely, 2^31131121311 is an apocalyptic number.

31131121311 is a deficient number, since it is larger than the sum of its proper divisors (18623643089).

31131121311 is a wasteful number, since it uses less digits than its factorization.

31131121311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331701 (or 331692 counting only the distinct ones).

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

Adding to 31131121311 its reverse (11312113113), we get a palindrome (42443234424).

The spelling of 31131121311 in words is "thirty-one billion, one hundred thirty-one million, one hundred twenty-one thousand, three hundred eleven".