21868266 has 32 divisors (see below), whose sum is σ = 50135040. Its totient is φ = 6229296.

The previous prime is 21868247. The next prime is 21868289. The reversal of 21868266 is 66286812.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19575 + ... + 20661.

It is an arithmetic number, because the mean of its divisors is an integer number (1566720).

Almost surely, 2^21868266 is an apocalyptic number.

21868266 is an abundant number, since it is smaller than the sum of its proper divisors (28266774).

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

21868266 is a wasteful number, since it uses less digits than its factorization.

21868266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1578.

The product of its digits is 55296, while the sum is 39.

The square root of 21868266 is about 4676.3517831746. The cubic root of 21868266 is about 279.6435344747.

The spelling of 21868266 in words is "twenty-one million, eight hundred sixty-eight thousand, two hundred sixty-six".