21921124 has 9 divisors (see below), whose sum is σ = 38378361. Its totient is φ = 10955880.

The previous prime is 21921121. The next prime is 21921167. The reversal of 21921124 is 42112912.

The square root of 21921124 is 4682.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 14303524 + 7617600 = 3782^2 + 2760^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21921095 and 21921104.

It is not an unprimeable number, because it can be changed into a prime (21921121) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 8194 + ... + 10534.

Almost surely, 2^21921124 is an apocalyptic number.

21921124 is the 4682-nd square number.

It is an amenable number.

21921124 is a deficient number, since it is larger than the sum of its proper divisors (16457237).

21921124 is an frugal number, since it uses more digits than its factorization.

21921124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4686 (or 2343 counting only the distinct ones).

The product of its digits is 288, while the sum is 22.

The cubic root of 21921124 is about 279.8686628943.

The spelling of 21921124 in words is "twenty-one million, nine hundred twenty-one thousand, one hundred twenty-four".