21166919968 has 96 divisors (see below), whose sum is σ = 44059680000. Its totient is φ = 9995166720.

The previous prime is 21166919951. The next prime is 21166919971. The reversal of 21166919968 is 86991966112.

It is a Harshad number since it is a multiple of its sum of digits (58).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11264053 + ... + 11265931.

It is an arithmetic number, because the mean of its divisors is an integer number (458955000).

Almost surely, 2^21166919968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21166919968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22029840000).

21166919968 is an abundant number, since it is smaller than the sum of its proper divisors (22892760032).

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

21166919968 is a wasteful number, since it uses less digits than its factorization.

21166919968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2178 (or 2170 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 58.

The spelling of 21166919968 in words is "twenty-one billion, one hundred sixty-six million, nine hundred nineteen thousand, nine hundred sixty-eight".