31601513 has 2 divisors, whose sum is σ = 31601514. Its totient is φ = 31601512.

The previous prime is 31601509. The next prime is 31601527. The reversal of 31601513 is 31510613.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31225744 + 375769 = 5588^2 + 613^2 .

It is a cyclic number.

It is not a de Polignac number, because 31601513 - 2² = 31601509 is a prime.

It is not a weakly prime, because it can be changed into another prime (31001513) 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, 15800756 + 15800757.

It is an arithmetic number, because the mean of its divisors is an integer number (15800757).

Almost surely, 2^31601513 is an apocalyptic number.

It is an amenable number.

31601513 is a deficient number, since it is larger than the sum of its proper divisors (1).

31601513 is an equidigital number, since it uses as much as digits as its factorization.

31601513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 31601513 is about 5621.5223027219. The cubic root of 31601513 is about 316.1568714520.

The spelling of 31601513 in words is "thirty-one million, six hundred one thousand, five hundred thirteen".