15761721768 has 256 divisors, whose sum is σ = 45904320000. Its totient is φ = 4467032064.

The previous prime is 15761721743. The next prime is 15761721803. The reversal of 15761721768 is 86712716751.

It is a Harshad number since it is a multiple of its sum of digits (51).

Its product of digits (987840) is a multiple of the sum of its prime divisors (480).

It is a self number, because there is not a number n which added to its sum of digits gives 15761721768.

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, 79204533 + ... + 79204731.

It is an arithmetic number, because the mean of its divisors is an integer number (179313750).

Almost surely, 2^15761721768 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 15761721768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22952160000).

15761721768 is an abundant number, since it is smaller than the sum of its proper divisors (30142598232).

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

15761721768 is a wasteful number, since it uses less digits than its factorization.

15761721768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484 (or 480 counting only the distinct ones).

The product of its digits is 987840, while the sum is 51.

The spelling of 15761721768 in words is "fifteen billion, seven hundred sixty-one million, seven hundred twenty-one thousand, seven hundred sixty-eight".