31997473 has 2 divisors, whose sum is σ = 31997474. Its totient is φ = 31997472.

The previous prime is 31997431. The next prime is 31997477. The reversal of 31997473 is 37479913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25070049 + 6927424 = 5007^2 + 2632^2 .

It is a cyclic number.

It is not a de Polignac number, because 31997473 - 2⁹ = 31996961 is a prime.

It is not a weakly prime, because it can be changed into another prime (31997477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15998736 + 15998737.

It is an arithmetic number, because the mean of its divisors is an integer number (15998737).

Almost surely, 2^31997473 is an apocalyptic number.

It is an amenable number.

31997473 is a deficient number, since it is larger than the sum of its proper divisors (1).

31997473 is an equidigital number, since it uses as much as digits as its factorization.

31997473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 142884, while the sum is 43.

The square root of 31997473 is about 5656.6308877281. The cubic root of 31997473 is about 317.4718531685.

The spelling of 31997473 in words is "thirty-one million, nine hundred ninety-seven thousand, four hundred seventy-three".