18617845853 has 4 divisors (see below), whose sum is σ = 18619196028. Its totient is φ = 18616495680.

The previous prime is 18617845823. The next prime is 18617845859. The reversal of 18617845853 is 35854871681.

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 10099848004 + 8517997849 = 100498^2 + 92293^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18617845853 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 (18617845859) 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, 654188 + ... + 682053.

It is an arithmetic number, because the mean of its divisors is an integer number (4654799007).

Almost surely, 2^18617845853 is an apocalyptic number.

It is an amenable number.

18617845853 is a deficient number, since it is larger than the sum of its proper divisors (1350175).

18617845853 is a wasteful number, since it uses less digits than its factorization.

18617845853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350174.

The product of its digits is 6451200, while the sum is 56.

The spelling of 18617845853 in words is "eighteen billion, six hundred seventeen million, eight hundred forty-five thousand, eight hundred fifty-three".