18007216 has 40 divisors (see below), whose sum is σ = 37229760. Its totient is φ = 8408064.

The previous prime is 18007207. The next prime is 18007237. The reversal of 18007216 is 61270081.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64870 + ... + 65146.

It is an arithmetic number, because the mean of its divisors is an integer number (930744).

Almost surely, 2^18007216 is an apocalyptic number.

18007216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18007216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18614880).

18007216 is an abundant number, since it is smaller than the sum of its proper divisors (19222544).

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

18007216 is a wasteful number, since it uses less digits than its factorization.

18007216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541 (or 535 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 18007216 is about 4243.4910156615. The cubic root of 18007216 is about 262.1091556123.

Adding to 18007216 its reverse (61270081), we get a palindrome (79277297).

The spelling of 18007216 in words is "eighteen million, seven thousand, two hundred sixteen".