15556665551 has 16 divisors (see below), whose sum is σ = 18365319168. Its totient is φ = 12895178400.

The previous prime is 15556665533. The next prime is 15556665571.

15556665551 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 15556665551 - 2¹⁴ = 15556649167 is a prime.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 15556665551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15556665521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 297641 + ... + 345981.

It is an arithmetic number, because the mean of its divisors is an integer number (1147832448).

Almost surely, 2^15556665551 is an apocalyptic number.

15556665551 is a deficient number, since it is larger than the sum of its proper divisors (2808653617).

15556665551 is a wasteful number, since it uses less digits than its factorization.

15556665551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49862.

The product of its digits is 3375000, while the sum is 50.

The spelling of 15556665551 in words is "fifteen billion, five hundred fifty-six million, six hundred sixty-five thousand, five hundred fifty-one".