21447445748736 has 2816 divisors, whose sum is σ = 80224058880000. Its totient is φ = 5049648414720.

The previous prime is 21447445748723. The next prime is 21447445748759. The reversal of 21447445748736 is 63784754474412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 404668787686 + ... + 404668787738.

Almost surely, 2^{21447445748736} 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 21447445748736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40112029440000).

21447445748736 is an abundant number, since it is smaller than the sum of its proper divisors (58776613131264).

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

21447445748736 is a wasteful number, since it uses less digits than its factorization.

21447445748736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203 (or 171 counting only the distinct ones).

The product of its digits is 505774080, while the sum is 66.

The spelling of 21447445748736 in words is "twenty-one trillion, four hundred forty-seven billion, four hundred forty-five million, seven hundred forty-eight thousand, seven hundred thirty-six".