2645640 has 48 divisors (see below), whose sum is σ = 8599500. Its totient is φ = 705408.

The previous prime is 2645639. The next prime is 2645647. The reversal of 2645640 is 465462.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2643876 + 1764 = 1626^2 + 42^2 .

It is a super-2 number, since 2×2645640² = 13998822019200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2645647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3315 + ... + 4034.

2^2645640 is an apocalyptic number.

2645640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2645640 is an abundant number, since it is smaller than the sum of its proper divisors (5953860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2645640 is a wasteful number, since it uses less digits than its factorization.

2645640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7366 (or 7359 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 2645640 is about 1626.5423449760. The cubic root of 2645640 is about 138.3068157748.

The spelling of 2645640 in words is "two million, six hundred forty-five thousand, six hundred forty".