18109804957 has 4 divisors (see below), whose sum is σ = 18734281020. Its totient is φ = 17485328896.

The previous prime is 18109804939. The next prime is 18109804961. The reversal of 18109804957 is 75940890181.

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 12041550756 + 6068254201 = 109734^2 + 77899^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18109804957 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 (18109802957) 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, 312237988 + ... + 312238045.

It is an arithmetic number, because the mean of its divisors is an integer number (4683570255).

Almost surely, 2^18109804957 is an apocalyptic number.

It is an amenable number.

18109804957 is a deficient number, since it is larger than the sum of its proper divisors (624476063).

18109804957 is an equidigital number, since it uses as much as digits as its factorization.

18109804957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624476062.

The product of its (nonzero) digits is 725760, while the sum is 52.

The spelling of 18109804957 in words is "eighteen billion, one hundred nine million, eight hundred four thousand, nine hundred fifty-seven".