21529922 has 18 divisors (see below), whose sum is σ = 34485003. Its totient is φ = 10079232.

The previous prime is 21529897. The next prime is 21529927. The reversal of 21529922 is 22992512.

It can be written as a sum of positive squares in 5 ways, for example, as 11296321 + 10233601 = 3361^2 + 3199^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3281.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21529927) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 111458 + ... + 111650.

Almost surely, 2^21529922 is an apocalyptic number.

21529922 is a deficient number, since it is larger than the sum of its proper divisors (12955081).

21529922 is an equidigital number, since it uses as much as digits as its factorization.

21529922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 212 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 21529922 is about 4640.0346981461. The cubic root of 21529922 is about 278.1938247717.

Multiplying 21529922 by its sum of digits (32), we get a square (688957504 = 26248²).

The spelling of 21529922 in words is "twenty-one million, five hundred twenty-nine thousand, nine hundred twenty-two".