31697137 has 4 divisors (see below), whose sum is σ = 31708656. Its totient is φ = 31685620.

The previous prime is 31697131. The next prime is 31697161. The reversal of 31697137 is 73179613.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 31697137 - 2²³ = 23308529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31697096 and 31697105.

It is not an unprimeable number, because it can be changed into a prime (31697131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1062 + ... + 8032.

It is an arithmetic number, because the mean of its divisors is an integer number (7927164).

Almost surely, 2^31697137 is an apocalyptic number.

It is an amenable number.

31697137 is a deficient number, since it is larger than the sum of its proper divisors (11519).

31697137 is an equidigital number, since it uses as much as digits as its factorization.

31697137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11518.

The product of its digits is 23814, while the sum is 37.

The square root of 31697137 is about 5630.0210479180. The cubic root of 31697137 is about 316.4754399789.

The spelling of 31697137 in words is "thirty-one million, six hundred ninety-seven thousand, one hundred thirty-seven".