21988972800 has 432 divisors, whose sum is σ = 81678730560. Its totient is φ = 5859993600.

The previous prime is 21988972781. The next prime is 21988972801. The reversal of 21988972800 is 827988912.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21988972801) 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 47 ways as a sum of consecutive naturals, for example, 13996015 + ... + 13997585.

Almost surely, 2^21988972800 is an apocalyptic number.

21988972800 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 21988972800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40839365280).

21988972800 is an abundant number, since it is smaller than the sum of its proper divisors (59689757760).

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

21988972800 is an frugal number, since it uses more digits than its factorization.

21988972800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618 (or 1581 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 54.

The spelling of 21988972800 in words is "twenty-one billion, nine hundred eighty-eight million, nine hundred seventy-two thousand, eight hundred".