2728561 has 4 divisors (see below), whose sum is σ = 2976624. Its totient is φ = 2480500.

The previous prime is 2728553. The next prime is 2728567. The reversal of 2728561 is 1658272.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2728561 - 2³ = 2728553 is a prime.

It is a d-powerful number, because it can be written as 2¹⁸ + 7³ + 2¹⁹ + 8⁶ + 5² + 6⁸ + 1 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2728567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124015 + ... + 124036.

It is an arithmetic number, because the mean of its divisors is an integer number (744156).

2^2728561 is an apocalyptic number.

It is an amenable number.

2728561 is a deficient number, since it is larger than the sum of its proper divisors (248063).

2728561 is a wasteful number, since it uses less digits than its factorization.

2728561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248062.

The product of its digits is 6720, while the sum is 31.

The square root of 2728561 is about 1651.8356455774. The cubic root of 2728561 is about 139.7369379851.

The spelling of 2728561 in words is "two million, seven hundred twenty-eight thousand, five hundred sixty-one".