31557401 has 2 divisors, whose sum is σ = 31557402. Its totient is φ = 31557400.

The previous prime is 31557391. The next prime is 31557431. The reversal of 31557401 is 10475513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31416025 + 141376 = 5605^2 + 376^2 .

It is a cyclic number.

It is not a de Polignac number, because 31557401 - 2¹⁴ = 31541017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (31557431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15778700 + 15778701.

It is an arithmetic number, because the mean of its divisors is an integer number (15778701).

Almost surely, 2^31557401 is an apocalyptic number.

It is an amenable number.

31557401 is a deficient number, since it is larger than the sum of its proper divisors (1).

31557401 is an equidigital number, since it uses as much as digits as its factorization.

31557401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 31557401 is about 5617.5974401874. The cubic root of 31557401 is about 316.0096969999.

The spelling of 31557401 in words is "thirty-one million, five hundred fifty-seven thousand, four hundred one".