2645865 has 40 divisors (see below), whose sum is σ = 4878720. Its totient is φ = 1371168.

The previous prime is 2645861. The next prime is 2645879. The reversal of 2645865 is 5685462.

2645865 is a `hidden beast` number, since 2 + 645 + 8 + 6 + 5 = 666.

It is not a de Polignac number, because 2645865 - 2² = 2645861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2645861) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 18966 + ... + 19104.

It is an arithmetic number, because the mean of its divisors is an integer number (121968).

2^2645865 is an apocalyptic number.

It is an amenable number.

2645865 is a deficient number, since it is larger than the sum of its proper divisors (2232855).

2645865 is a wasteful number, since it uses less digits than its factorization.

2645865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203 (or 194 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The square root of 2645865 is about 1626.6115086277. The cubic root of 2645865 is about 138.3107364583.

The spelling of 2645865 in words is "two million, six hundred forty-five thousand, eight hundred sixty-five".