18000018216 has 48 divisors (see below), whose sum is σ = 49417872660. Its totient is φ = 5917812480.

The previous prime is 18000018161. The next prime is 18000018221. The reversal of 18000018216 is 61281000081.

It can be written as a sum of positive squares in 2 ways, for example, as 17997295716 + 2722500 = 134154^2 + 1650^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18000018216.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1707075 + ... + 1717586.

Almost surely, 2^18000018216 is an apocalyptic number.

It is an amenable number.

18000018216 is an abundant number, since it is smaller than the sum of its proper divisors (31417854444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18000018216 is a wasteful number, since it uses less digits than its factorization.

18000018216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3424746 (or 3424739 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

Adding to 18000018216 its reverse (61281000081), we get a palindrome (79281018297).

The spelling of 18000018216 in words is "eighteen billion, eighteen thousand, two hundred sixteen".