21920590 has 8 divisors (see below), whose sum is σ = 39457080. Its totient is φ = 8768232.

The previous prime is 21920573. The next prime is 21920621. The reversal of 21920590 is 9502912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1096020 + ... + 1096039.

It is an arithmetic number, because the mean of its divisors is an integer number (4932135).

Almost surely, 2^21920590 is an apocalyptic number.

21920590 is a deficient number, since it is larger than the sum of its proper divisors (17536490).

21920590 is a wasteful number, since it uses less digits than its factorization.

21920590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2192066.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 21920590 is about 4681.9429727411. The cubic root of 21920590 is about 279.8663903363.

The spelling of 21920590 in words is "twenty-one million, nine hundred twenty thousand, five hundred ninety".