18209216 has 28 divisors (see below), whose sum is σ = 37383720. Its totient is φ = 8789760.

The previous prime is 18209209. The next prime is 18209231. The reversal of 18209216 is 61290281.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3050 + ... + 6761.

Almost surely, 2^18209216 is an apocalyptic number.

18209216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18209216 is an abundant number, since it is smaller than the sum of its proper divisors (19174504).

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

18209216 is an equidigital number, since it uses as much as digits as its factorization.

18209216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9852 (or 9842 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 18209216 is about 4267.2257966974. The cubic root of 18209216 is about 263.0856029805.

Adding to 18209216 its reverse (61290281), we get a palindrome (79499497).

The spelling of 18209216 in words is "eighteen million, two hundred nine thousand, two hundred sixteen".