18318478693 has 2 divisors, whose sum is σ = 18318478694. Its totient is φ = 18318478692.

The previous prime is 18318478681. The next prime is 18318478699. The reversal of 18318478693 is 39687481381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16663453569 + 1655025124 = 129087^2 + 40682^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18318478693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18318478699) 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, 9159239346 + 9159239347.

It is an arithmetic number, because the mean of its divisors is an integer number (9159239347).

Almost surely, 2^18318478693 is an apocalyptic number.

It is an amenable number.

18318478693 is a deficient number, since it is larger than the sum of its proper divisors (1).

18318478693 is an equidigital number, since it uses as much as digits as its factorization.

18318478693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6967296, while the sum is 58.

The spelling of 18318478693 in words is "eighteen billion, three hundred eighteen million, four hundred seventy-eight thousand, six hundred ninety-three".