31945131 has 16 divisors (see below), whose sum is σ = 48035200. Its totient is φ = 20977704.

The previous prime is 31945073. The next prime is 31945139. The reversal of 31945131 is 13154913.

It is not a de Polignac number, because 31945131 - 2¹¹ = 31943083 is a prime.

It is a super-2 number, since 2×31945131² = 2040982789214322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31945095 and 31945104.

It is not an unprimeable number, because it can be changed into a prime (31945139) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7021 + ... + 10638.

It is an arithmetic number, because the mean of its divisors is an integer number (3002200).

Almost surely, 2^31945131 is an apocalyptic number.

31945131 is a deficient number, since it is larger than the sum of its proper divisors (16090069).

31945131 is a wasteful number, since it uses less digits than its factorization.

31945131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17735 (or 17729 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 31945131 is about 5652.0023885345. The cubic root of 31945131 is about 317.2986501072.

Subtracting from 31945131 its sum of digits (27), we obtain a square (31945104 = 5652²).

The spelling of 31945131 in words is "thirty-one million, nine hundred forty-five thousand, one hundred thirty-one".