2781728 has 12 divisors (see below), whose sum is σ = 5476590. Its totient is φ = 1390848.

The previous prime is 2781707. The next prime is 2781731. The reversal of 2781728 is 8271872.

It can be written as a sum of positive squares in only one way, i.e., 2598544 + 183184 = 1612^2 + 428^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43433 + ... + 43496.

2^2781728 is an apocalyptic number.

It is an amenable number.

2781728 is a deficient number, since it is larger than the sum of its proper divisors (2694862).

2781728 is an equidigital number, since it uses as much as digits as its factorization.

2781728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86939 (or 86931 counting only the distinct ones).

The product of its digits is 12544, while the sum is 35.

The square root of 2781728 is about 1667.8513123177. The cubic root of 2781728 is about 140.6387142510.

The spelling of 2781728 in words is "two million, seven hundred eighty-one thousand, seven hundred twenty-eight".