18728216 has 64 divisors (see below), whose sum is σ = 40346880. Its totient is φ = 8087040.

The previous prime is 18728197. The next prime is 18728249. The reversal of 18728216 is 61282781.

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 15 ways as a sum of consecutive naturals, for example, 119210 + ... + 119366.

It is an arithmetic number, because the mean of its divisors is an integer number (630420).

Almost surely, 2^18728216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18728216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20173440).

18728216 is an abundant number, since it is smaller than the sum of its proper divisors (21618664).

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

18728216 is a wasteful number, since it uses less digits than its factorization.

18728216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 240 counting only the distinct ones).

The product of its digits is 10752, while the sum is 35.

The square root of 18728216 is about 4327.6108882385. The cubic root of 18728216 is about 265.5617181846.

The spelling of 18728216 in words is "eighteen million, seven hundred twenty-eight thousand, two hundred sixteen".