18642117543855 has 32 divisors (see below), whose sum is σ = 32122018865664. Its totient is φ = 9177596059776.

The previous prime is 18642117543853. The next prime is 18642117543913. The reversal of 18642117543855 is 55834571124681.

It is not a de Polignac number, because 18642117543855 - 2¹ = 18642117543853 is a prime.

It is a super-2 number, since 2×18642117543855² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18642117543853) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45094102 + ... + 45505628.

It is an arithmetic number, because the mean of its divisors is an integer number (1003813089552).

Almost surely, 2^{18642117543855} is an apocalyptic number.

18642117543855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18642117543855 is a deficient number, since it is larger than the sum of its proper divisors (13479901321809).

18642117543855 is a wasteful number, since it uses less digits than its factorization.

18642117543855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643855.

The product of its digits is 32256000, while the sum is 60.

The spelling of 18642117543855 in words is "eighteen trillion, six hundred forty-two billion, one hundred seventeen million, five hundred forty-three thousand, eight hundred fifty-five".