21520264 has 16 divisors (see below), whose sum is σ = 40492620. Its totient is φ = 10722240.

The previous prime is 21520243. The next prime is 21520271. The reversal of 21520264 is 46202512.

It can be written as a sum of positive squares in 2 ways, for example, as 18992164 + 2528100 = 4358^2 + 1590^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2247 + ... + 6934.

Almost surely, 2^21520264 is an apocalyptic number.

It is an amenable number.

21520264 is a deficient number, since it is larger than the sum of its proper divisors (18972356).

21520264 is a wasteful number, since it uses less digits than its factorization.

21520264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9480 (or 9476 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21520264 is about 4638.9938564305. The cubic root of 21520264 is about 278.1522206914.

Adding to 21520264 its reverse (46202512), we get a palindrome (67722776).

The spelling of 21520264 in words is "twenty-one million, five hundred twenty thousand, two hundred sixty-four".