21905991868992 has 448 divisors, whose sum is σ = 72698111152128. Its totient is φ = 5655527424000.

The previous prime is 21905991868973. The next prime is 21905991869023. The reversal of 21905991868992 is 29986819950912.

It is a tau number, because it is divible by the number of its divisors (448).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4311351892 + ... + 4311356972.

It is an arithmetic number, because the mean of its divisors is an integer number (162272569536).

Almost surely, 2^{21905991868992} is an apocalyptic number.

21905991868992 is a gapful number since it is divisible by the number (22) 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 21905991868992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36349055576064).

21905991868992 is an abundant number, since it is smaller than the sum of its proper divisors (50792119283136).

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

21905991868992 is a wasteful number, since it uses less digits than its factorization.

21905991868992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6818 (or 6808 counting only the distinct ones).

The product of its (nonzero) digits is 453496320, while the sum is 78.

The spelling of 21905991868992 in words is "twenty-one trillion, nine hundred five billion, nine hundred ninety-one million, eight hundred sixty-eight thousand, nine hundred ninety-two".