21828790 has 16 divisors (see below), whose sum is σ = 39675168. Its totient is φ = 8646336.

The previous prime is 21828767. The next prime is 21828791. The reversal of 21828790 is 9782812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21828791) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9567 + ... + 11626.

It is an arithmetic number, because the mean of its divisors is an integer number (2479698).

Almost surely, 2^21828790 is an apocalyptic number.

21828790 is a deficient number, since it is larger than the sum of its proper divisors (17846378).

21828790 is a wasteful number, since it uses less digits than its factorization.

21828790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21303.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 21828790 is about 4672.1290649981. The cubic root of 21828790 is about 279.4751648168.

The spelling of 21828790 in words is "twenty-one million, eight hundred twenty-eight thousand, seven hundred ninety".