21884790 has 16 divisors (see below), whose sum is σ = 52523568. Its totient is φ = 5835936.

The previous prime is 21884783. The next prime is 21884809. The reversal of 21884790 is 9748812.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 364717 + ... + 364776.

It is an arithmetic number, because the mean of its divisors is an integer number (3282723).

Almost surely, 2^21884790 is an apocalyptic number.

21884790 is an abundant number, since it is smaller than the sum of its proper divisors (30638778).

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

21884790 is a wasteful number, since it uses less digits than its factorization.

21884790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729503.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 21884790 is about 4678.1182114179. The cubic root of 21884790 is about 279.7139510683.

The spelling of 21884790 in words is "twenty-one million, eight hundred eighty-four thousand, seven hundred ninety".