31997153 has 2 divisors, whose sum is σ = 31997154. Its totient is φ = 31997152.

The previous prime is 31997149. The next prime is 31997171. The reversal of 31997153 is 35179913.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31719424 + 277729 = 5632^2 + 527^2 .

It is an emirp because it is prime and its reverse (35179913) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31997153 - 2² = 31997149 is a prime.

It is not a weakly prime, because it can be changed into another prime (31997113) 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, 15998576 + 15998577.

It is an arithmetic number, because the mean of its divisors is an integer number (15998577).

Almost surely, 2^31997153 is an apocalyptic number.

It is an amenable number.

31997153 is a deficient number, since it is larger than the sum of its proper divisors (1).

31997153 is an equidigital number, since it uses as much as digits as its factorization.

31997153 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25515, while the sum is 38.

The square root of 31997153 is about 5656.6026022693. The cubic root of 31997153 is about 317.4707948419.

The spelling of 31997153 in words is "thirty-one million, nine hundred ninety-seven thousand, one hundred fifty-three".