21528984 has 32 divisors (see below), whose sum is σ = 53951040. Its totient is φ = 7159200.

The previous prime is 21528937. The next prime is 21529003. The reversal of 21528984 is 48982512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12919 + ... + 14489.

It is an arithmetic number, because the mean of its divisors is an integer number (1685970).

Almost surely, 2^21528984 is an apocalyptic number.

21528984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21528984 is an abundant number, since it is smaller than the sum of its proper divisors (32422056).

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

21528984 is a wasteful number, since it uses less digits than its factorization.

21528984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151 (or 2147 counting only the distinct ones).

The product of its digits is 46080, while the sum is 39.

The square root of 21528984 is about 4639.9336202148. The cubic root of 21528984 is about 278.1897846642.

The spelling of 21528984 in words is "twenty-one million, five hundred twenty-eight thousand, nine hundred eighty-four".