18685877117 has 2 divisors, whose sum is σ = 18685877118. Its totient is φ = 18685877116.

The previous prime is 18685877071. The next prime is 18685877167. The reversal of 18685877117 is 71177858681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18449517241 + 236359876 = 135829^2 + 15374^2 .

It is a cyclic number.

It is not a de Polignac number, because 18685877117 - 2⁸ = 18685876861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18685877167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9342938558 + 9342938559.

It is an arithmetic number, because the mean of its divisors is an integer number (9342938559).

Almost surely, 2^18685877117 is an apocalyptic number.

It is an amenable number.

18685877117 is a deficient number, since it is larger than the sum of its proper divisors (1).

18685877117 is an equidigital number, since it uses as much as digits as its factorization.

18685877117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5268480, while the sum is 59.

The spelling of 18685877117 in words is "eighteen billion, six hundred eighty-five million, eight hundred seventy-seven thousand, one hundred seventeen".