18537102197 has 4 divisors (see below), whose sum is σ = 18538483500. Its totient is φ = 18535720896.

The previous prime is 18537102187. The next prime is 18537102217. The reversal of 18537102197 is 79120173581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79120173581 = 23 ⋅3440007547.

It can be written as a sum of positive squares in 2 ways, for example, as 14486288881 + 4050813316 = 120359^2 + 63646^2 .

It is a cyclic number.

It is not a de Polignac number, because 18537102197 - 2¹⁸ = 18536840053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18537102187) 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 in 3 ways as a sum of consecutive naturals, for example, 670322 + ... + 697427.

It is an arithmetic number, because the mean of its divisors is an integer number (4634620875).

Almost surely, 2^18537102197 is an apocalyptic number.

It is an amenable number.

18537102197 is a deficient number, since it is larger than the sum of its proper divisors (1381303).

18537102197 is a wasteful number, since it uses less digits than its factorization.

18537102197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1381302.

The product of its (nonzero) digits is 105840, while the sum is 44.

The spelling of 18537102197 in words is "eighteen billion, five hundred thirty-seven million, one hundred two thousand, one hundred ninety-seven".