30997665 has 24 divisors (see below), whose sum is σ = 55584360. Its totient is φ = 15961344.

The previous prime is 30997657. The next prime is 30997667. The reversal of 30997665 is 56679903.

It can be written as a sum of positive squares in 4 ways, for example, as 5716881 + 25280784 = 2391^2 + 5028^2 .

It is not a de Polignac number, because 30997665 - 2³ = 30997657 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 30997665.

It is not an unprimeable number, because it can be changed into a prime (30997667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10572 + ... + 13181.

It is an arithmetic number, because the mean of its divisors is an integer number (2316015).

Almost surely, 2^30997665 is an apocalyptic number.

It is an amenable number.

30997665 is a deficient number, since it is larger than the sum of its proper divisors (24586695).

30997665 is a wasteful number, since it uses less digits than its factorization.

30997665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23793 (or 23790 counting only the distinct ones).

The product of its (nonzero) digits is 306180, while the sum is 45.

The square root of 30997665 is about 5567.5546696912. The cubic root of 30997665 is about 314.1301778112.

The spelling of 30997665 in words is "thirty million, nine hundred ninety-seven thousand, six hundred sixty-five".