21528124 has 12 divisors (see below), whose sum is σ = 37769200. Its totient is φ = 10736928.

The previous prime is 21528113. The next prime is 21528127. The reversal of 21528124 is 42182512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21528127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4944 + ... + 8215.

Almost surely, 2^21528124 is an apocalyptic number.

It is an amenable number.

21528124 is a deficient number, since it is larger than the sum of its proper divisors (16241076).

21528124 is a wasteful number, since it uses less digits than its factorization.

21528124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13572 (or 13570 counting only the distinct ones).

The product of its digits is 1280, while the sum is 25.

The square root of 21528124 is about 4639.8409455498. The cubic root of 21528124 is about 278.1860804114.

The spelling of 21528124 in words is "twenty-one million, five hundred twenty-eight thousand, one hundred twenty-four".