31240931 has 2 divisors, whose sum is σ = 31240932. Its totient is φ = 31240930.

The previous prime is 31240889. The next prime is 31240933. The reversal of 31240931 is 13904213.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31240931 is a prime.

It is a super-2 number, since 2×31240931² = 1951991539493522, which contains 22 as substring.

Together with 31240933, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31240897 and 31240906.

It is not a weakly prime, because it can be changed into another prime (31240933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15620465 + 15620466.

It is an arithmetic number, because the mean of its divisors is an integer number (15620466).

Almost surely, 2^31240931 is an apocalyptic number.

31240931 is a deficient number, since it is larger than the sum of its proper divisors (1).

31240931 is an equidigital number, since it uses as much as digits as its factorization.

31240931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 31240931 is about 5589.3587288704. The cubic root of 31240931 is about 314.9497895950.

The spelling of 31240931 in words is "thirty-one million, two hundred forty thousand, nine hundred thirty-one".