31097239 has 2 divisors, whose sum is σ = 31097240. Its totient is φ = 31097238.

The previous prime is 31097191. The next prime is 31097249. The reversal of 31097239 is 93279013.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31097239 - 2⁷ = 31097111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31097249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15548619 + 15548620.

It is an arithmetic number, because the mean of its divisors is an integer number (15548620).

Almost surely, 2^31097239 is an apocalyptic number.

31097239 is a deficient number, since it is larger than the sum of its proper divisors (1).

31097239 is an equidigital number, since it uses as much as digits as its factorization.

31097239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 31097239 is about 5576.4898457722. The cubic root of 31097239 is about 314.4661790893.

The spelling of 31097239 in words is "thirty-one million, ninety-seven thousand, two hundred thirty-nine".