21880890 has 24 divisors (see below), whose sum is σ = 56890548. Its totient is φ = 5834880.

The previous prime is 21880879. The next prime is 21880919. The reversal of 21880890 is 9808812.

It can be written as a sum of positive squares in 2 ways, for example, as 21874329 + 6561 = 4677^2 + 81^2 .

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, 121471 + ... + 121650.

Almost surely, 2^21880890 is an apocalyptic number.

21880890 is an abundant number, since it is smaller than the sum of its proper divisors (35009658).

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

21880890 is a wasteful number, since it uses less digits than its factorization.

21880890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243134 (or 243131 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 21880890 is about 4677.7013585735. The cubic root of 21880890 is about 279.6973345168.

The spelling of 21880890 in words is "twenty-one million, eight hundred eighty thousand, eight hundred ninety".