2649865 has 4 divisors (see below), whose sum is σ = 3179844. Its totient is φ = 2119888.

The previous prime is 2649863. The next prime is 2649869. The reversal of 2649865 is 5689462.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5689462 = 2 ⋅2844731.

It can be written as a sum of positive squares in 2 ways, for example, as 2005056 + 644809 = 1416^2 + 803^2 .

It is a cyclic number.

It is not a de Polignac number, because 2649865 - 2¹ = 2649863 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

2649865 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2649863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264982 + ... + 264991.

It is an arithmetic number, because the mean of its divisors is an integer number (794961).

2^2649865 is an apocalyptic number.

It is an amenable number.

2649865 is a deficient number, since it is larger than the sum of its proper divisors (529979).

2649865 is an equidigital number, since it uses as much as digits as its factorization.

2649865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529978.

The product of its digits is 103680, while the sum is 40.

The square root of 2649865 is about 1627.8405941615. The cubic root of 2649865 is about 138.3804004288.

The spelling of 2649865 in words is "two million, six hundred forty-nine thousand, eight hundred sixty-five".