18516908638091 has 2 divisors, whose sum is σ = 18516908638092. Its totient is φ = 18516908638090.

The previous prime is 18516908638031. The next prime is 18516908638099. The reversal of 18516908638091 is 19083680961581.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18516908638091 - 2³⁰ = 18515834896267 is a prime.

It is a super-2 number, since 2×18516908638091² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18516908638099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9258454319045 + 9258454319046.

It is an arithmetic number, because the mean of its divisors is an integer number (9258454319046).

Almost surely, 2^{18516908638091} is an apocalyptic number.

18516908638091 is a deficient number, since it is larger than the sum of its proper divisors (1).

18516908638091 is an equidigital number, since it uses as much as digits as its factorization.

18516908638091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22394880, while the sum is 65.

The spelling of 18516908638091 in words is "eighteen trillion, five hundred sixteen billion, nine hundred eight million, six hundred thirty-eight thousand, ninety-one".