21020568 has 32 divisors (see below), whose sum is σ = 55643760. Its totient is φ = 6594560.

The previous prime is 21020543. The next prime is 21020581. The reversal of 21020568 is 86502012.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

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, 25353 + ... + 26168.

Almost surely, 2^21020568 is an apocalyptic number.

It is an amenable number.

21020568 is an abundant number, since it is smaller than the sum of its proper divisors (34623192).

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

21020568 is a wasteful number, since it uses less digits than its factorization.

21020568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51547 (or 51543 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 21020568 is about 4584.8192985111. The cubic root of 21020568 is about 275.9824605531.

The spelling of 21020568 in words is "twenty-one million, twenty thousand, five hundred sixty-eight".