21828900 has 36 divisors (see below), whose sum is σ = 63159152. Its totient is φ = 5820960.

The previous prime is 21828899. The next prime is 21828913. The reversal of 21828900 is 982812.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 36082 + ... + 36681.

Almost surely, 2^21828900 is an apocalyptic number.

21828900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21828900 is an abundant number, since it is smaller than the sum of its proper divisors (41330252).

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

21828900 is a wasteful number, since it uses less digits than its factorization.

21828900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72780 (or 72773 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 21828900 is about 4672.1408369183. The cubic root of 21828900 is about 279.4756342613.

The spelling of 21828900 in words is "twenty-one million, eight hundred twenty-eight thousand, nine hundred".