21684552 has 32 divisors (see below), whose sum is σ = 54902400. Its totient is φ = 7136064.

The previous prime is 21684527. The next prime is 21684557. The reversal of 21684552 is 25548612.

It is not an unprimeable number, because it can be changed into a prime (21684557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3823 + ... + 7614.

It is an arithmetic number, because the mean of its divisors is an integer number (1715700).

Almost surely, 2^21684552 is an apocalyptic number.

It is an amenable number.

21684552 is an abundant number, since it is smaller than the sum of its proper divisors (33217848).

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

21684552 is a wasteful number, since it uses less digits than its factorization.

21684552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11525 (or 11521 counting only the distinct ones).

The product of its digits is 19200, while the sum is 33.

The square root of 21684552 is about 4656.6674779288. The cubic root of 21684552 is about 278.8582417278.

The spelling of 21684552 in words is "twenty-one million, six hundred eighty-four thousand, five hundred fifty-two".