18685179761 has 2 divisors, whose sum is σ = 18685179762. Its totient is φ = 18685179760.

The previous prime is 18685179727. The next prime is 18685179763. The reversal of 18685179761 is 16797158681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15741466225 + 2943713536 = 125465^2 + 54256^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18685179761 is a prime.

Together with 18685179763, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18685179761.

It is not a weakly prime, because it can be changed into another prime (18685179763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9342589880 + 9342589881.

It is an arithmetic number, because the mean of its divisors is an integer number (9342589881).

Almost surely, 2^18685179761 is an apocalyptic number.

It is an amenable number.

18685179761 is a deficient number, since it is larger than the sum of its proper divisors (1).

18685179761 is an equidigital number, since it uses as much as digits as its factorization.

18685179761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 59.

The spelling of 18685179761 in words is "eighteen billion, six hundred eighty-five million, one hundred seventy-nine thousand, seven hundred sixty-one".