18815218155 has 24 divisors (see below), whose sum is σ = 32648222880. Its totient is φ = 10023959040.

The previous prime is 18815218127. The next prime is 18815218157. The reversal of 18815218155 is 55181251881.

It is not a de Polignac number, because 18815218155 - 2¹⁰ = 18815217131 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 18815218155.

It is not an unprimeable number, because it can be changed into a prime (18815218157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 183231 + ... + 266840.

It is an arithmetic number, because the mean of its divisors is an integer number (1360342620).

Almost surely, 2^18815218155 is an apocalyptic number.

18815218155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18815218155 is a deficient number, since it is larger than the sum of its proper divisors (13833004725).

18815218155 is a wasteful number, since it uses less digits than its factorization.

18815218155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451011 (or 451008 counting only the distinct ones).

The product of its digits is 128000, while the sum is 45.

The spelling of 18815218155 in words is "eighteen billion, eight hundred fifteen million, two hundred eighteen thousand, one hundred fifty-five".