2155728 has 40 divisors (see below), whose sum is σ = 5638528. Its totient is φ = 709632.

The previous prime is 2155723. The next prime is 2155733. The reversal of 2155728 is 8275512.

It is an interprime number because it is at equal distance from previous prime (2155723) and next prime (2155733).

It is a junction number, because it is equal to n+sod(n) for n = 2155695 and 2155704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155723) 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, 4425 + ... + 4887.

2^2155728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2155728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2819264).

2155728 is an abundant number, since it is smaller than the sum of its proper divisors (3482800).

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

2155728 is a wasteful number, since it uses less digits than its factorization.

2155728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571 (or 565 counting only the distinct ones).

The product of its digits is 5600, while the sum is 30.

The square root of 2155728 is about 1468.2397624366. The cubic root of 2155728 is about 129.1808052970.

The spelling of 2155728 in words is "two million, one hundred fifty-five thousand, seven hundred twenty-eight".