21566652 has 24 divisors (see below), whose sum is σ = 50480976. Its totient is φ = 7166208.

The previous prime is 21566647. The next prime is 21566681. The reversal of 21566652 is 25666512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1378 + ... + 6710.

It is an arithmetic number, because the mean of its divisors is an integer number (2103374).

Almost surely, 2^21566652 is an apocalyptic number.

It is an amenable number.

21566652 is an abundant number, since it is smaller than the sum of its proper divisors (28914324).

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

21566652 is a wasteful number, since it uses less digits than its factorization.

21566652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5677 (or 5675 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 21566652 is about 4643.9909560635. The cubic root of 21566652 is about 278.3519342472.

The spelling of 21566652 in words is "twenty-one million, five hundred sixty-six thousand, six hundred fifty-two".