31281649 has 27 divisors (see below), whose sum is σ = 39495243. Its totient is φ = 24698688.

The previous prime is 31281643. The next prime is 31281661. The reversal of 31281649 is 94618213.

The square root of 31281649 is 5593.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 24354225 + 6927424 = 4935^2 + 2632^2 .

It is not a de Polignac number, because 31281649 - 2⁵ = 31281617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31281643) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 665544 + ... + 665590.

Almost surely, 2^31281649 is an apocalyptic number.

31281649 is the 5593-rd square number.

31281649 is the 2797-th centered octagonal number.

It is an amenable number.

31281649 is a deficient number, since it is larger than the sum of its proper divisors (8213594).

31281649 is an equidigital number, since it uses as much as digits as its factorization.

31281649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 71 counting only the distinct ones).

The product of its digits is 10368, while the sum is 34.

The cubic root of 31281649 is about 315.0865605735.

The spelling of 31281649 in words is "thirty-one million, two hundred eighty-one thousand, six hundred forty-nine".