21890826 has 24 divisors (see below), whose sum is σ = 48210084. Its totient is φ = 7176960.

The previous prime is 21890807. The next prime is 21890839. The reversal of 21890826 is 62809812.

It can be written as a sum of positive squares in 2 ways, for example, as 17264025 + 4626801 = 4155^2 + 2151^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8871 + ... + 11066.

Almost surely, 2^21890826 is an apocalyptic number.

21890826 is an abundant number, since it is smaller than the sum of its proper divisors (26319258).

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

21890826 is a wasteful number, since it uses less digits than its factorization.

21890826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20006 (or 20003 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 21890826 is about 4678.7632981377. The cubic root of 21890826 is about 279.7396644855.

The spelling of 21890826 in words is "twenty-one million, eight hundred ninety thousand, eight hundred twenty-six".