21975668 has 48 divisors (see below), whose sum is σ = 45741696. Its totient is φ = 9106560.

The previous prime is 21975637. The next prime is 21975691. The reversal of 21975668 is 86657912.

It is a Harshad number since it is a multiple of its sum of digits (44).

Its product of digits (181440) is a multiple of the sum of its prime factors (504).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 58730 + ... + 59102.

It is an arithmetic number, because the mean of its divisors is an integer number (952952).

Almost surely, 2^21975668 is an apocalyptic number.

It is an amenable number.

21975668 is an abundant number, since it is smaller than the sum of its proper divisors (23766028).

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

21975668 is a wasteful number, since it uses less digits than its factorization.

21975668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504 (or 502 counting only the distinct ones).

The product of its digits is 181440, while the sum is 44.

The square root of 21975668 is about 4687.8212423257. The cubic root of 21975668 is about 280.1005931082.

The spelling of 21975668 in words is "twenty-one million, nine hundred seventy-five thousand, six hundred sixty-eight".