18551358966 has 128 divisors (see below), whose sum is σ = 45438935040. Its totient is φ = 4945237920.

The previous prime is 18551358961. The next prime is 18551358977. The reversal of 18551358966 is 66985315581.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18551358961) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20453085 + ... + 20453991.

It is an arithmetic number, because the mean of its divisors is an integer number (354991680).

Almost surely, 2^18551358966 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18551358966, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22719467520).

18551358966 is an abundant number, since it is smaller than the sum of its proper divisors (26887576074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18551358966 is an equidigital number, since it uses as much as digits as its factorization.

18551358966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1047 (or 1009 counting only the distinct ones).

The product of its digits is 7776000, while the sum is 57.

The spelling of 18551358966 in words is "eighteen billion, five hundred fifty-one million, three hundred fifty-eight thousand, nine hundred sixty-six".