2728721 has 8 divisors (see below), whose sum is σ = 2911104. Its totient is φ = 2548800.

The previous prime is 2728711. The next prime is 2728741. The reversal of 2728721 is 1278272.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2728721 - 2⁶ = 2728657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2728711) 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, 2036 + ... + 3098.

It is an arithmetic number, because the mean of its divisors is an integer number (363888).

2^2728721 is an apocalyptic number.

It is an amenable number.

2728721 is a deficient number, since it is larger than the sum of its proper divisors (182383).

2728721 is a wasteful number, since it uses less digits than its factorization.

2728721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1231.

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

The square root of 2728721 is about 1651.8840758358. The cubic root of 2728721 is about 139.7396692749.

The spelling of 2728721 in words is "two million, seven hundred twenty-eight thousand, seven hundred twenty-one".