18218397271 has 4 divisors (see below), whose sum is σ = 18398777544. Its totient is φ = 18038017000.

The previous prime is 18218397257. The next prime is 18218397287. The reversal of 18218397271 is 17279381281.

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

It is a cyclic number.

It is not a de Polignac number, because 18218397271 - 2⁹ = 18218396759 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 (18218397971) 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, 90189985 + ... + 90190186.

It is an arithmetic number, because the mean of its divisors is an integer number (4599694386).

Almost surely, 2^18218397271 is an apocalyptic number.

18218397271 is a deficient number, since it is larger than the sum of its proper divisors (180380273).

18218397271 is a wasteful number, since it uses less digits than its factorization.

18218397271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180380272.

The product of its digits is 338688, while the sum is 49.

The spelling of 18218397271 in words is "eighteen billion, two hundred eighteen million, three hundred ninety-seven thousand, two hundred seventy-one".