18216378291 has 8 divisors (see below), whose sum is σ = 24318019840. Its totient is φ = 12129494472.

The previous prime is 18216378277. The next prime is 18216378329. The reversal of 18216378291 is 19287361281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18216378291 - 2⁶ = 18216378227 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18216378291.

It is not an unprimeable number, because it can be changed into a prime (18216378221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3686551 + ... + 3691488.

It is an arithmetic number, because the mean of its divisors is an integer number (3039752480).

Almost surely, 2^18216378291 is an apocalyptic number.

18216378291 is a deficient number, since it is larger than the sum of its proper divisors (6101641549).

18216378291 is an equidigital number, since it uses as much as digits as its factorization.

18216378291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7378865.

The product of its digits is 290304, while the sum is 48.

The spelling of 18216378291 in words is "eighteen billion, two hundred sixteen million, three hundred seventy-eight thousand, two hundred ninety-one".