18657891197 has 16 divisors (see below), whose sum is σ = 20927579904. Its totient is φ = 16486848000.

The previous prime is 18657891193. The next prime is 18657891227. The reversal of 18657891197 is 79119875681.

It is a cyclic number.

It is not a de Polignac number, because 18657891197 - 2² = 18657891193 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18657891193) 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 in 15 ways as a sum of consecutive naturals, for example, 45893 + ... + 198549.

It is an arithmetic number, because the mean of its divisors is an integer number (1307973744).

Almost surely, 2^18657891197 is an apocalyptic number.

It is an amenable number.

18657891197 is a deficient number, since it is larger than the sum of its proper divisors (2269688707).

18657891197 is a wasteful number, since it uses less digits than its factorization.

18657891197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152980.

The product of its digits is 7620480, while the sum is 62.

The spelling of 18657891197 in words is "eighteen billion, six hundred fifty-seven million, eight hundred ninety-one thousand, one hundred ninety-seven".