2499865 has 4 divisors (see below), whose sum is σ = 2999844. Its totient is φ = 1999888.

The previous prime is 2499863. The next prime is 2499881. The reversal of 2499865 is 5689942.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5689942 = 2 ⋅2844971.

It can be written as a sum of positive squares in 2 ways, for example, as 1646089 + 853776 = 1283^2 + 924^2 .

It is a cyclic number.

It is not a de Polignac number, because 2499865 - 2¹ = 2499863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2499863) 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, 249982 + ... + 249991.

It is an arithmetic number, because the mean of its divisors is an integer number (749961).

2^2499865 is an apocalyptic number.

It is an amenable number.

2499865 is a deficient number, since it is larger than the sum of its proper divisors (499979).

2499865 is an equidigital number, since it uses as much as digits as its factorization.

2499865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499978.

The product of its digits is 155520, while the sum is 43.

The square root of 2499865 is about 1581.0961387594. The cubic root of 2499865 is about 135.7184378099.

It can be divided in two parts, 2499 and 865, that added together give a square (3364 = 58²).

The spelling of 2499865 in words is "two million, four hundred ninety-nine thousand, eight hundred sixty-five".