15555665855 has 4 divisors (see below), whose sum is σ = 18666799032. Its totient is φ = 12444532680.

The previous prime is 15555665813. The next prime is 15555665891. The reversal of 15555665855 is 55856655551.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 15555665855 - 2⁸ = 15555665599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15555665855.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1555566581 + ... + 1555566590.

It is an arithmetic number, because the mean of its divisors is an integer number (4666699758).

Almost surely, 2^15555665855 is an apocalyptic number.

15555665855 is a deficient number, since it is larger than the sum of its proper divisors (3111133177).

15555665855 is an equidigital number, since it uses as much as digits as its factorization.

15555665855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3111133176.

The product of its digits is 22500000, while the sum is 56.

The spelling of 15555665855 in words is "fifteen billion, five hundred fifty-five million, six hundred sixty-five thousand, eight hundred fifty-five".