15550666605551 has 12 divisors (see below), whose sum is σ = 19534721687376. Its totient is φ = 12117402549120.

The previous prime is 15550666605517. The next prime is 15550666605563.

15550666605551 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 15550666605551 - 2²⁶ = 15550599496687 is a prime.

It is a hoax number, since the sum of its digits (56) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15550666605511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9179849570 + ... + 9179851263.

It is an arithmetic number, because the mean of its divisors is an integer number (1627893473948).

Almost surely, 2^{15550666605551} is an apocalyptic number.

15550666605551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

15550666605551 is a deficient number, since it is larger than the sum of its proper divisors (3984055081825).

15550666605551 is a wasteful number, since it uses less digits than its factorization.

15550666605551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18359700862 (or 18359700851 counting only the distinct ones).

The product of its (nonzero) digits is 20250000, while the sum is 56.

The spelling of 15550666605551 in words is "fifteen trillion, five hundred fifty billion, six hundred sixty-six million, six hundred five thousand, five hundred fifty-one".