18191879149 has 2 divisors, whose sum is σ = 18191879150. Its totient is φ = 18191879148.

The previous prime is 18191879093. The next prime is 18191879239. The reversal of 18191879149 is 94197819181.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17399456649 + 792422500 = 131907^2 + 28150^2 .

It is a cyclic number.

It is not a de Polignac number, because 18191879149 - 2⁷ = 18191879021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18191879093 and 18191879102.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18191879449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9095939574 + 9095939575.

It is an arithmetic number, because the mean of its divisors is an integer number (9095939575).

Almost surely, 2^18191879149 is an apocalyptic number.

It is an amenable number.

18191879149 is a deficient number, since it is larger than the sum of its proper divisors (1).

18191879149 is an equidigital number, since it uses as much as digits as its factorization.

18191879149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1306368, while the sum is 58.

The spelling of 18191879149 in words is "eighteen billion, one hundred ninety-one million, eight hundred seventy-nine thousand, one hundred forty-nine".