21915912672 has 144 divisors (see below), whose sum is σ = 65724946560. Its totient is φ = 6908011776.

The previous prime is 21915912659. The next prime is 21915912701. The reversal of 21915912672 is 27621951912.

It is a tau number, because it is divible by the number of its divisors (144).

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, 3208653 + ... + 3215475.

It is an arithmetic number, because the mean of its divisors is an integer number (456423240).

Almost surely, 2^21915912672 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 21915912672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32862473280).

21915912672 is an abundant number, since it is smaller than the sum of its proper divisors (43809033888).

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

21915912672 is a wasteful number, since it uses less digits than its factorization.

21915912672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7445 (or 7434 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The spelling of 21915912672 in words is "twenty-one billion, nine hundred fifteen million, nine hundred twelve thousand, six hundred seventy-two".