21921411456 has 192 divisors, whose sum is σ = 75262230000. Its totient is φ = 6263212032.

The previous prime is 21921411439. The next prime is 21921411467. The reversal of 21921411456 is 65411412912.

21921411456 is a `hidden beast` number, since 2 + 192 + 1 + 4 + 11 + 456 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21921411456.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104620 + ... + 234068.

Almost surely, 2^21921411456 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 21921411456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37631115000).

21921411456 is an abundant number, since it is smaller than the sum of its proper divisors (53340818544).

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

21921411456 is a wasteful number, since it uses less digits than its factorization.

21921411456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129486 (or 129461 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The spelling of 21921411456 in words is "twenty-one billion, nine hundred twenty-one million, four hundred eleven thousand, four hundred fifty-six".