18524972117 has 4 divisors (see below), whose sum is σ = 18528359916. Its totient is φ = 18521584320.

The previous prime is 18524972111. The next prime is 18524972119. The reversal of 18524972117 is 71127942581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71127942581 = 178091 ⋅399391.

It can be written as a sum of positive squares in 2 ways, for example, as 18513956356 + 11015761 = 136066^2 + 3319^2 .

It is a cyclic number.

It is not a de Polignac number, because 18524972117 - 2²⁰ = 18523923541 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 (18524972111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1685684 + ... + 1696637.

It is an arithmetic number, because the mean of its divisors is an integer number (4632089979).

Almost surely, 2^18524972117 is an apocalyptic number.

It is an amenable number.

18524972117 is a deficient number, since it is larger than the sum of its proper divisors (3387799).

18524972117 is an equidigital number, since it uses as much as digits as its factorization.

18524972117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3387798.

The product of its digits is 282240, while the sum is 47.

The spelling of 18524972117 in words is "eighteen billion, five hundred twenty-four million, nine hundred seventy-two thousand, one hundred seventeen".