2721728 has 42 divisors (see below), whose sum is σ = 5769864. Its totient is φ = 1271424.

The previous prime is 2721727. The next prime is 2721767. The reversal of 2721728 is 8271272.

It is a self number, because there is not a number n which added to its sum of digits gives 2721728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2721721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 63275 + ... + 63317.

2^2721728 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 2721728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2884932).

2721728 is an abundant number, since it is smaller than the sum of its proper divisors (3048136).

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

2721728 is an equidigital number, since it uses as much as digits as its factorization.

2721728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 68 counting only the distinct ones).

The product of its digits is 3136, while the sum is 29.

The square root of 2721728 is about 1649.7660440196. The cubic root of 2721728 is about 139.6201950516.

The spelling of 2721728 in words is "two million, seven hundred twenty-one thousand, seven hundred twenty-eight".