18351216 has 60 divisors (see below), whose sum is σ = 55314168. Its totient is φ = 5645952.

The previous prime is 18351209. The next prime is 18351257. The reversal of 18351216 is 61215381.

It is a self number, because there is not a number n which added to its sum of digits gives 18351216.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3030 + ... + 6773.

Almost surely, 2^18351216 is an apocalyptic number.

18351216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18351216 is an abundant number, since it is smaller than the sum of its proper divisors (36962952).

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

18351216 is a wasteful number, since it uses less digits than its factorization.

18351216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9830 (or 9821 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 18351216 is about 4283.8319294762. The cubic root of 18351216 is about 263.7677019931.

Adding to 18351216 its product of digits (1440), we get a square (18352656 = 4284²).

Adding to 18351216 its reverse (61215381), we get a palindrome (79566597).

The spelling of 18351216 in words is "eighteen million, three hundred fifty-one thousand, two hundred sixteen".