18271538993 has 4 divisors (see below), whose sum is σ = 19233198960. Its totient is φ = 17309879028.

The previous prime is 18271538977. The next prime is 18271539017. The reversal of 18271538993 is 39983517281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18271538993 - 2⁴ = 18271538977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18271538933) 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, 480829955 + ... + 480829992.

It is an arithmetic number, because the mean of its divisors is an integer number (4808299740).

Almost surely, 2^18271538993 is an apocalyptic number.

It is an amenable number.

18271538993 is a deficient number, since it is larger than the sum of its proper divisors (961659967).

18271538993 is an equidigital number, since it uses as much as digits as its factorization.

18271538993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961659966.

The product of its digits is 3265920, while the sum is 56.

The spelling of 18271538993 in words is "eighteen billion, two hundred seventy-one million, five hundred thirty-eight thousand, nine hundred ninety-three".