2181228 has 48 divisors (see below), whose sum is σ = 6074880. Its totient is φ = 595584.

The previous prime is 2181227. The next prime is 2181229. The reversal of 2181228 is 8221812.

It is an interprime number because it is at equal distance from previous prime (2181227) and next prime (2181229).

It is a junction number, because it is equal to n+sod(n) for n = 2181198 and 2181207.

It is not an unprimeable number, because it can be changed into a prime (2181227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1368 + ... + 2496.

It is an arithmetic number, because the mean of its divisors is an integer number (126560).

2^2181228 is an apocalyptic number.

2181228 is a gapful number since it is divisible by the number (28) 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 2181228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3037440).

2181228 is an abundant number, since it is smaller than the sum of its proper divisors (3893652).

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

2181228 is a wasteful number, since it uses less digits than its factorization.

2181228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1166 (or 1164 counting only the distinct ones).

The product of its digits is 512, while the sum is 24.

The square root of 2181228 is about 1476.8981007504. The cubic root of 2181228 is about 129.6881677906.

It can be divided in two parts, 218122 and 8, that added together give a triangular number (218130 = T₆₆₀).

The spelling of 2181228 in words is "two million, one hundred eighty-one thousand, two hundred twenty-eight".