18538723873 has 4 divisors (see below), whose sum is σ = 19629237060. Its totient is φ = 17448210688.

The previous prime is 18538723829. The next prime is 18538723883. The reversal of 18538723873 is 37832783581.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6734335969 + 11804387904 = 82063^2 + 108648^2 .

It is a cyclic number.

It is not a de Polignac number, because 18538723873 - 2⁹ = 18538723361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18538723813) 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 3 ways as a sum of consecutive naturals, for example, 545256568 + ... + 545256601.

It is an arithmetic number, because the mean of its divisors is an integer number (4907309265).

Almost surely, 2^18538723873 is an apocalyptic number.

It is an amenable number.

18538723873 is a deficient number, since it is larger than the sum of its proper divisors (1090513187).

18538723873 is a wasteful number, since it uses less digits than its factorization.

18538723873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090513186.

The product of its digits is 6773760, while the sum is 55.

The spelling of 18538723873 in words is "eighteen billion, five hundred thirty-eight million, seven hundred twenty-three thousand, eight hundred seventy-three".