31310491 has 2 divisors, whose sum is σ = 31310492. Its totient is φ = 31310490.

The previous prime is 31310471. The next prime is 31310497. The reversal of 31310491 is 19401313.

It is a strong prime.

It is an emirp because it is prime and its reverse (19401313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31310491 - 2²³ = 22921883 is a prime.

It is a super-2 number, since 2×31310491² = 1960693693322162, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31310497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15655245 + 15655246.

It is an arithmetic number, because the mean of its divisors is an integer number (15655246).

Almost surely, 2^31310491 is an apocalyptic number.

31310491 is a deficient number, since it is larger than the sum of its proper divisors (1).

31310491 is an equidigital number, since it uses as much as digits as its factorization.

31310491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 31310491 is about 5595.5778075191. The cubic root of 31310491 is about 315.1833685031.

The spelling of 31310491 in words is "thirty-one million, three hundred ten thousand, four hundred ninety-one".