18423845813 has 16 divisors (see below), whose sum is σ = 19051686192. Its totient is φ = 17805312000.

The previous prime is 18423845809. The next prime is 18423845821. The reversal of 18423845813 is 31854832481.

It can be written as a sum of positive squares in 8 ways, for example, as 7119478129 + 11304367684 = 84377^2 + 106322^2 .

It is a cyclic number.

It is not a de Polignac number, because 18423845813 - 2² = 18423845809 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18423845113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1902203 + ... + 1911863.

It is an arithmetic number, because the mean of its divisors is an integer number (1190730387).

Almost surely, 2^18423845813 is an apocalyptic number.

It is an amenable number.

18423845813 is a deficient number, since it is larger than the sum of its proper divisors (627840379).

18423845813 is a wasteful number, since it uses less digits than its factorization.

18423845813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10136.

The product of its digits is 737280, while the sum is 47.

The spelling of 18423845813 in words is "eighteen billion, four hundred twenty-three million, eight hundred forty-five thousand, eight hundred thirteen".