18240228 has 60 divisors (see below), whose sum is σ = 50210160. Its totient is φ = 5758128.

The previous prime is 18240227. The next prime is 18240239. The reversal of 18240228 is 82204281.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18240221) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 4675 + ... + 7637.

It is an arithmetic number, because the mean of its divisors is an integer number (836836).

Almost surely, 2^18240228 is an apocalyptic number.

18240228 is a gapful number since it is divisible by the number (18) 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 18240228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25105080).

18240228 is an abundant number, since it is smaller than the sum of its proper divisors (31969932).

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

18240228 is a wasteful number, since it uses less digits than its factorization.

18240228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2998 (or 2987 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 18240228 is about 4270.8579934247. The cubic root of 18240228 is about 263.2348714125.

The spelling of 18240228 in words is "eighteen million, two hundred forty thousand, two hundred twenty-eight".