2188728 has 32 divisors (see below), whose sum is σ = 6080400. Its totient is φ = 729504.

The previous prime is 2188691. The next prime is 2188729. The reversal of 2188728 is 8278812.

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 = 2188692 and 2188701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2188729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4851 + ... + 5282.

2^2188728 is an apocalyptic number.

It is an amenable number.

2188728 is an abundant number, since it is smaller than the sum of its proper divisors (3891672).

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

2188728 is a wasteful number, since it uses less digits than its factorization.

2188728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10148 (or 10138 counting only the distinct ones).

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

The square root of 2188728 is about 1479.4350272993. The cubic root of 2188728 is about 129.8366389842.

It can be divided in two parts, 2188 and 728, that added together give a square (2916 = 54²).

The spelling of 2188728 in words is "two million, one hundred eighty-eight thousand, seven hundred twenty-eight".