18897228 has 144 divisors (see below), whose sum is σ = 58705920. Its totient is φ = 5011200.

The previous prime is 18897227. The next prime is 18897233. The reversal of 18897228 is 82279881.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (18897227) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 320263 + ... + 320321.

It is an arithmetic number, because the mean of its divisors is an integer number (407680).

Almost surely, 2^18897228 is an apocalyptic number.

18897228 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 18897228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29352960).

18897228 is an abundant number, since it is smaller than the sum of its proper divisors (39808692).

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

18897228 is a wasteful number, since it uses less digits than its factorization.

18897228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 143 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 18897228 is about 4347.0942018778. The cubic root of 18897228 is about 266.3581772940.

The spelling of 18897228 in words is "eighteen million, eight hundred ninety-seven thousand, two hundred twenty-eight".