21864000 has 112 divisors (see below), whose sum is σ = 72274176. Its totient is φ = 5824000.

The previous prime is 21863993. The next prime is 21864013. The reversal of 21864000 is 46812.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

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 15 ways as a sum of consecutive naturals, for example, 23545 + ... + 24455.

Almost surely, 2^21864000 is an apocalyptic number.

21864000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21864000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36137088).

21864000 is an abundant number, since it is smaller than the sum of its proper divisors (50410176).

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

21864000 is an equidigital number, since it uses as much as digits as its factorization.

21864000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 941 (or 921 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21864000 is about 4675.8956361322. The cubic root of 21864000 is about 279.6253492667.

The spelling of 21864000 in words is "twenty-one million, eight hundred sixty-four thousand".