21825564 has 24 divisors (see below), whose sum is σ = 51235968. Its totient is φ = 7230960.

The previous prime is 21825533. The next prime is 21825577. The reversal of 21825564 is 46552812.

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, 3442 + ... + 7449.

It is an arithmetic number, because the mean of its divisors is an integer number (2134832).

Almost surely, 2^21825564 is an apocalyptic number.

It is an amenable number.

21825564 is an abundant number, since it is smaller than the sum of its proper divisors (29410404).

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

21825564 is a wasteful number, since it uses less digits than its factorization.

21825564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11065 (or 11063 counting only the distinct ones).

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

The square root of 21825564 is about 4671.7838134914. The cubic root of 21825564 is about 279.4613965884.

The spelling of 21825564 in words is "twenty-one million, eight hundred twenty-five thousand, five hundred sixty-four".