18551116273 has 2 divisors, whose sum is σ = 18551116274. Its totient is φ = 18551116272.

The previous prime is 18551116267. The next prime is 18551116327. The reversal of 18551116273 is 37261115581.

Together with next prime (18551116327) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15950932209 + 2600184064 = 126297^2 + 50992^2 .

It is an emirp because it is prime and its reverse (37261115581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18551116273 - 2²⁵ = 18517561841 is a prime.

It is not a weakly prime, because it can be changed into another prime (18551110273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9275558136 + 9275558137.

It is an arithmetic number, because the mean of its divisors is an integer number (9275558137).

Almost surely, 2^18551116273 is an apocalyptic number.

It is an amenable number.

18551116273 is a deficient number, since it is larger than the sum of its proper divisors (1).

18551116273 is an equidigital number, since it uses as much as digits as its factorization.

18551116273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 40.

The spelling of 18551116273 in words is "eighteen billion, five hundred fifty-one million, one hundred sixteen thousand, two hundred seventy-three".