2640728 has 32 divisors (see below), whose sum is σ = 5186160. Its totient is φ = 1259520.

The previous prime is 2640721. The next prime is 2640739. The reversal of 2640728 is 8270462.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2640728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640721) 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, 27176 + ... + 27272.

2^2640728 is an apocalyptic number.

It is an amenable number.

2640728 is a deficient number, since it is larger than the sum of its proper divisors (2545432).

2640728 is a wasteful number, since it uses less digits than its factorization.

2640728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227 (or 223 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 2640728 is about 1625.0316919987. The cubic root of 2640728 is about 138.2211674430.

The spelling of 2640728 in words is "two million, six hundred forty thousand, seven hundred twenty-eight".