31725131 has 2 divisors, whose sum is σ = 31725132. Its totient is φ = 31725130.

The previous prime is 31725097. The next prime is 31725139. The reversal of 31725131 is 13152713.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31725131 - 2²² = 27530827 is a prime.

It is a super-2 number, since 2×31725131² = 2012967873934322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31725097 and 31725106.

It is not a weakly prime, because it can be changed into another prime (31725139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15862565 + 15862566.

It is an arithmetic number, because the mean of its divisors is an integer number (15862566).

Almost surely, 2^31725131 is an apocalyptic number.

31725131 is a deficient number, since it is larger than the sum of its proper divisors (1).

31725131 is an equidigital number, since it uses as much as digits as its factorization.

31725131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 630, while the sum is 23.

The square root of 31725131 is about 5632.5066355931. The cubic root of 31725131 is about 316.5685799011.

Adding to 31725131 its reverse (13152713), we get a palindrome (44877844).

The spelling of 31725131 in words is "thirty-one million, seven hundred twenty-five thousand, one hundred thirty-one".