31711397 has 2 divisors, whose sum is σ = 31711398. Its totient is φ = 31711396.

The previous prime is 31711391. The next prime is 31711403. The reversal of 31711397 is 79311713.

It is a balanced prime because it is at equal distance from previous prime (31711391) and next prime (31711403).

It can be written as a sum of positive squares in only one way, i.e., 29931841 + 1779556 = 5471^2 + 1334^2 .

It is a cyclic number.

It is not a de Polignac number, because 31711397 - 2²² = 27517093 is a prime.

It is a super-2 number, since 2×31711397² = 2011225399383218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31711391) 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, 15855698 + 15855699.

It is an arithmetic number, because the mean of its divisors is an integer number (15855699).

Almost surely, 2^31711397 is an apocalyptic number.

It is an amenable number.

31711397 is a deficient number, since it is larger than the sum of its proper divisors (1).

31711397 is an equidigital number, since it uses as much as digits as its factorization.

31711397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3969, while the sum is 32.

The square root of 31711397 is about 5631.2873306199. The cubic root of 31711397 is about 316.5228918269.

The spelling of 31711397 in words is "thirty-one million, seven hundred eleven thousand, three hundred ninety-seven".