21965530 has 16 divisors (see below), whose sum is σ = 41864040. Its totient is φ = 8269312.

The previous prime is 21965527. The next prime is 21965563. The reversal of 21965530 is 3556912.

It can be written as a sum of positive squares in 4 ways, for example, as 14220441 + 7745089 = 3771^2 + 2783^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21965492 and 21965501.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64435 + ... + 64774.

Almost surely, 2^21965530 is an apocalyptic number.

21965530 is a deficient number, since it is larger than the sum of its proper divisors (19898510).

21965530 is a wasteful number, since it uses less digits than its factorization.

21965530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129233.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 21965530 is about 4686.7398050244. The cubic root of 21965530 is about 280.0575136957.

The spelling of 21965530 in words is "twenty-one million, nine hundred sixty-five thousand, five hundred thirty".