11551721559 has 16 divisors (see below), whose sum is σ = 17604303360. Its totient is φ = 6600353760.

The previous prime is 11551721543. The next prime is 11551721647. The reversal of 11551721559 is 95512715511.

It is not a de Polignac number, because 11551721559 - 2⁴ = 11551721543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11551721559.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11551721509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 284662 + ... + 322700.

It is an arithmetic number, because the mean of its divisors is an integer number (1100268960).

Almost surely, 2^11551721559 is an apocalyptic number.

11551721559 is a deficient number, since it is larger than the sum of its proper divisors (6052581801).

11551721559 is a wasteful number, since it uses less digits than its factorization.

11551721559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52510.

The product of its digits is 78750, while the sum is 42.

The spelling of 11551721559 in words is "eleven billion, five hundred fifty-one million, seven hundred twenty-one thousand, five hundred fifty-nine".