21822790 has 32 divisors (see below), whose sum is σ = 44336160. Its totient is φ = 7660800.

The previous prime is 21822763. The next prime is 21822793. The reversal of 21822790 is 9722812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21822793) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 231 + ... + 6610.

It is an arithmetic number, because the mean of its divisors is an integer number (1385505).

Almost surely, 2^21822790 is an apocalyptic number.

21822790 is an abundant number, since it is smaller than the sum of its proper divisors (22513370).

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

21822790 is a wasteful number, since it uses less digits than its factorization.

21822790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6888.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21822790 is about 4671.4869153194. The cubic root of 21822790 is about 279.4495563635.

The spelling of 21822790 in words is "twenty-one million, eight hundred twenty-two thousand, seven hundred ninety".