21026568 has 16 divisors (see below), whose sum is σ = 52566480. Its totient is φ = 7008848.

The previous prime is 21026567. The next prime is 21026573. The reversal of 21026568 is 86562012.

It is not an unprimeable number, because it can be changed into a prime (21026567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 438030 + ... + 438077.

It is an arithmetic number, because the mean of its divisors is an integer number (3285405).

Almost surely, 2^21026568 is an apocalyptic number.

It is an amenable number.

21026568 is an abundant number, since it is smaller than the sum of its proper divisors (31539912).

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

21026568 is a wasteful number, since it uses less digits than its factorization.

21026568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876116 (or 876112 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 21026568 is about 4585.4735851382. The cubic root of 21026568 is about 276.0087163809.

The spelling of 21026568 in words is "twenty-one million, twenty-six thousand, five hundred sixty-eight".