21816916800 has 1008 divisors, whose sum is σ = 90050843520. Its totient is φ = 4598415360.

The previous prime is 21816916769. The next prime is 21816916811. The reversal of 21816916800 is 861961812.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 200155146 + ... + 200155254.

Almost surely, 2^21816916800 is an apocalyptic number.

21816916800 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 21816916800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45025421760).

21816916800 is an abundant number, since it is smaller than the sum of its proper divisors (68233926720).

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

21816916800 is a wasteful number, since it uses less digits than its factorization.

21816916800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 186 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 42.

The spelling of 21816916800 in words is "twenty-one billion, eight hundred sixteen million, nine hundred sixteen thousand, eight hundred".