2640305 has 16 divisors (see below), whose sum is σ = 3326400. Its totient is φ = 2009280.

The previous prime is 2640299. The next prime is 2640317. The reversal of 2640305 is 5030462.

It is not a de Polignac number, because 2640305 - 2⁴ = 2640289 is a prime.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18926 + ... + 19064.

It is an arithmetic number, because the mean of its divisors is an integer number (207900).

2^2640305 is an apocalyptic number.

It is an amenable number.

2640305 is a deficient number, since it is larger than the sum of its proper divisors (686095).

2640305 is a wasteful number, since it uses less digits than its factorization.

2640305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 2640305 is about 1624.9015354784. The cubic root of 2640305 is about 138.2137868172.

Adding to 2640305 its reverse (5030462), we get a palindrome (7670767).

The spelling of 2640305 in words is "two million, six hundred forty thousand, three hundred five".