18870228 has 72 divisors (see below), whose sum is σ = 52290056. Its totient is φ = 5702400.

The previous prime is 18870217. The next prime is 18870233. The reversal of 18870228 is 82207881.

It can be written as a sum of positive squares in 4 ways, for example, as 51984 + 18818244 = 228^2 + 4338^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18870192 and 18870201.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28218 + ... + 28878.

Almost surely, 2^18870228 is an apocalyptic number.

18870228 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 18870228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26145028).

18870228 is an abundant number, since it is smaller than the sum of its proper divisors (33419828).

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

18870228 is a wasteful number, since it uses less digits than its factorization.

18870228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745 (or 740 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 18870228 is about 4343.9875690430. The cubic root of 18870228 is about 266.2312609968.

The spelling of 18870228 in words is "eighteen million, eight hundred seventy thousand, two hundred twenty-eight".