21866800 has 30 divisors (see below), whose sum is σ = 52535948. Its totient is φ = 8746560.

The previous prime is 21866773. The next prime is 21866809. The reversal of 21866800 is 866812.

It is not an unprimeable number, because it can be changed into a prime (21866809) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 26934 + ... + 27733.

Almost surely, 2^21866800 is an apocalyptic number.

21866800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21866800 is an abundant number, since it is smaller than the sum of its proper divisors (30669148).

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

21866800 is a wasteful number, since it uses less digits than its factorization.

21866800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54685 (or 54674 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 21866800 is about 4676.1950344270. The cubic root of 21866800 is about 279.6372854412.

The spelling of 21866800 in words is "twenty-one million, eight hundred sixty-six thousand, eight hundred".