31697131 has 2 divisors, whose sum is σ = 31697132. Its totient is φ = 31697130.

The previous prime is 31697089. The next prime is 31697161. The reversal of 31697131 is 13179613.

It is a strong prime.

It is an emirp because it is prime and its reverse (13179613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31697131 - 2¹³ = 31688939 is a prime.

It is a super-2 number, since 2×31697131² = 2009416227262322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31697093 and 31697102.

It is not a weakly prime, because it can be changed into another prime (31697161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15848565 + 15848566.

It is an arithmetic number, because the mean of its divisors is an integer number (15848566).

Almost surely, 2^31697131 is an apocalyptic number.

31697131 is a deficient number, since it is larger than the sum of its proper divisors (1).

31697131 is an equidigital number, since it uses as much as digits as its factorization.

31697131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3402, while the sum is 31.

The square root of 31697131 is about 5630.0205150603. The cubic root of 31697131 is about 316.4754200102.

The spelling of 31697131 in words is "thirty-one million, six hundred ninety-seven thousand, one hundred thirty-one".