31997243 has 2 divisors, whose sum is σ = 31997244. Its totient is φ = 31997242.

The previous prime is 31997233. The next prime is 31997249. The reversal of 31997243 is 34279913.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31997243 - 2⁴ = 31997227 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31997197 and 31997206.

It is not a weakly prime, because it can be changed into another prime (31997249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15998621 + 15998622.

It is an arithmetic number, because the mean of its divisors is an integer number (15998622).

Almost surely, 2^31997243 is an apocalyptic number.

31997243 is a deficient number, since it is larger than the sum of its proper divisors (1).

31997243 is an equidigital number, since it uses as much as digits as its factorization.

31997243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 38.

The square root of 31997243 is about 5656.6105575689. The cubic root of 31997243 is about 317.4710924970.

The spelling of 31997243 in words is "thirty-one million, nine hundred ninety-seven thousand, two hundred forty-three".