18871698117 has 4 divisors (see below), whose sum is σ = 25162264160. Its totient is φ = 12581132076.

The previous prime is 18871698103. The next prime is 18871698163. The reversal of 18871698117 is 71189617881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18871698117 - 2¹¹ = 18871696069 is a prime.

It is a super-2 number, since 2×18871698117² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18871698017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3145283017 + ... + 3145283022.

It is an arithmetic number, because the mean of its divisors is an integer number (6290566040).

Almost surely, 2^18871698117 is an apocalyptic number.

It is an amenable number.

18871698117 is a deficient number, since it is larger than the sum of its proper divisors (6290566043).

18871698117 is an equidigital number, since it uses as much as digits as its factorization.

18871698117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6290566042.

The product of its digits is 1354752, while the sum is 57.

The spelling of 18871698117 in words is "eighteen billion, eight hundred seventy-one million, six hundred ninety-eight thousand, one hundred seventeen".