31970321 has 2 divisors, whose sum is σ = 31970322. Its totient is φ = 31970320.

The previous prime is 31970261. The next prime is 31970333. The reversal of 31970321 is 12307913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28206721 + 3763600 = 5311^2 + 1940^2 .

It is a cyclic number.

It is not a de Polignac number, because 31970321 - 2²² = 27776017 is a prime.

It is not a weakly prime, because it can be changed into another prime (31970221) 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, 15985160 + 15985161.

It is an arithmetic number, because the mean of its divisors is an integer number (15985161).

Almost surely, 2^31970321 is an apocalyptic number.

It is an amenable number.

31970321 is a deficient number, since it is larger than the sum of its proper divisors (1).

31970321 is an equidigital number, since it uses as much as digits as its factorization.

31970321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 31970321 is about 5654.2303631883. The cubic root of 31970321 is about 317.3820290427.

The spelling of 31970321 in words is "thirty-one million, nine hundred seventy thousand, three hundred twenty-one".