18195694117 has 2 divisors, whose sum is σ = 18195694118. Its totient is φ = 18195694116.

The previous prime is 18195694073. The next prime is 18195694159. The reversal of 18195694117 is 71149659181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11705941636 + 6489752481 = 108194^2 + 80559^2 .

It is a cyclic number.

It is not a de Polignac number, because 18195694117 - 2¹⁵ = 18195661349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18195694177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9097847058 + 9097847059.

It is an arithmetic number, because the mean of its divisors is an integer number (9097847059).

Almost surely, 2^18195694117 is an apocalyptic number.

It is an amenable number.

18195694117 is a deficient number, since it is larger than the sum of its proper divisors (1).

18195694117 is an equidigital number, since it uses as much as digits as its factorization.

18195694117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 544320, while the sum is 52.

The spelling of 18195694117 in words is "eighteen billion, one hundred ninety-five million, six hundred ninety-four thousand, one hundred seventeen".