21163968000 has 960 divisors, whose sum is σ = 90620449920. Its totient is φ = 4644864000.

The previous prime is 21163967927. The next prime is 21163968013. The reversal of 21163968000 is 86936112.

21163968000 is a `hidden beast` number, since 2 + 11 + 639 + 6 + 8 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 116927910 + ... + 116928090.

It is an arithmetic number, because the mean of its divisors is an integer number (94396302).

Almost surely, 2^21163968000 is an apocalyptic number.

21163968000 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 21163968000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45310224960).

21163968000 is an abundant number, since it is smaller than the sum of its proper divisors (69456481920).

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

21163968000 is a wasteful number, since it uses less digits than its factorization.

21163968000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The spelling of 21163968000 in words is "twenty-one billion, one hundred sixty-three million, nine hundred sixty-eight thousand".