2640256 has 16 divisors (see below), whose sum is σ = 5260140. Its totient is φ = 1320064.

The previous prime is 2640251. The next prime is 2640271. The reversal of 2640256 is 6520462.

It is a tau number, because it is divible by the number of its divisors (16).

It is a self number, because there is not a number n which added to its sum of digits gives 2640256.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10186 + ... + 10441.

2^2640256 is an apocalyptic number.

It is an amenable number.

2640256 is a deficient number, since it is larger than the sum of its proper divisors (2619884).

2640256 is an equidigital number, since it uses as much as digits as its factorization.

2640256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20641 (or 20629 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 2640256 is about 1624.8864575717. The cubic root of 2640256 is about 138.2129318001.

Subtracting from 2640256 its product of nonzero digits (2880), we obtain a square (2637376 = 1624²).

The spelling of 2640256 in words is "two million, six hundred forty thousand, two hundred fifty-six".