21866980 has 24 divisors (see below), whose sum is σ = 46202688. Its totient is φ = 8693088.

The previous prime is 21866941. The next prime is 21866989. The reversal of 21866980 is 8966812.

It is not an unprimeable number, because it can be changed into a prime (21866989) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 67 + ... + 6613.

It is an arithmetic number, because the mean of its divisors is an integer number (1925112).

Almost surely, 2^21866980 is an apocalyptic number.

21866980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21866980 is an abundant number, since it is smaller than the sum of its proper divisors (24335708).

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

21866980 is a wasteful number, since it uses less digits than its factorization.

21866980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6723 (or 6721 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 21866980 is about 4676.2142808045. The cubic root of 21866980 is about 279.6380527318.

The spelling of 21866980 in words is "twenty-one million, eight hundred sixty-six thousand, nine hundred eighty".