31021649 has 2 divisors, whose sum is σ = 31021650. Its totient is φ = 31021648.

The previous prime is 31021637. The next prime is 31021663. The reversal of 31021649 is 94612013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27636049 + 3385600 = 5257^2 + 1840^2 .

It is a cyclic number.

It is not a de Polignac number, because 31021649 - 2⁴ = 31021633 is a prime.

It is not a weakly prime, because it can be changed into another prime (31027649) 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, 15510824 + 15510825.

It is an arithmetic number, because the mean of its divisors is an integer number (15510825).

Almost surely, 2^31021649 is an apocalyptic number.

It is an amenable number.

31021649 is a deficient number, since it is larger than the sum of its proper divisors (1).

31021649 is an equidigital number, since it uses as much as digits as its factorization.

31021649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 31021649 is about 5569.7081611158. The cubic root of 31021649 is about 314.2111748356.

The spelling of 31021649 in words is "thirty-one million, twenty-one thousand, six hundred forty-nine".