31697161 has 2 divisors, whose sum is σ = 31697162. Its totient is φ = 31697160.

The previous prime is 31697131. The next prime is 31697173. The reversal of 31697161 is 16179613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22278400 + 9418761 = 4720^2 + 3069^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31697161 is a prime.

It is not a weakly prime, because it can be changed into another prime (31697131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15848580 + 15848581.

It is an arithmetic number, because the mean of its divisors is an integer number (15848581).

Almost surely, 2^31697161 is an apocalyptic number.

It is an amenable number.

31697161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31697161 is an equidigital number, since it uses as much as digits as its factorization.

31697161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6804, while the sum is 34.

The square root of 31697161 is about 5630.0231793484. The cubic root of 31697161 is about 316.4755198537.

The spelling of 31697161 in words is "thirty-one million, six hundred ninety-seven thousand, one hundred sixty-one".