21264570 has 48 divisors (see below), whose sum is σ = 55528200. Its totient is φ = 5645952.

The previous prime is 21264563. The next prime is 21264577. The reversal of 21264570 is 7546212.

21264570 is a `hidden beast` number, since 2 + 12 + 645 + 7 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21264563) and next prime (21264577).

It can be written as a sum of positive squares in 4 ways, for example, as 21261321 + 3249 = 4611^2 + 57^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21264577) 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, 31072 + ... + 31748.

Almost surely, 2^21264570 is an apocalyptic number.

21264570 is an abundant number, since it is smaller than the sum of its proper divisors (34263630).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21264570 is a wasteful number, since it uses less digits than its factorization.

21264570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1039 (or 1036 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21264570 is about 4611.3522962359. The cubic root of 21264570 is about 277.0462025483.

The spelling of 21264570 in words is "twenty-one million, two hundred sixty-four thousand, five hundred seventy".