21971260768 has 72 divisors (see below), whose sum is σ = 46223894808. Its totient is φ = 10244677632.

The previous prime is 21971260723. The next prime is 21971260777. The reversal of 21971260768 is 86706217912.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6944755 + ... + 6947917.

It is an arithmetic number, because the mean of its divisors is an integer number (641998539).

Almost surely, 2^21971260768 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 21971260768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23111947404).

21971260768 is an abundant number, since it is smaller than the sum of its proper divisors (24252634040).

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

21971260768 is a wasteful number, since it uses less digits than its factorization.

21971260768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3416 (or 3295 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 49.

The spelling of 21971260768 in words is "twenty-one billion, nine hundred seventy-one million, two hundred sixty thousand, seven hundred sixty-eight".