24865 has 4 divisors (see below), whose sum is σ = 29844. Its totient is φ = 19888.

The previous prime is 24859. The next prime is 24877. The reversal of 24865 is 56842.

24865 = 111² + 112².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12544 + 12321 = 112^2 + 111^2 .

It is a cyclic number.

It is not a de Polignac number, because 24865 - 2¹¹ = 22817 is a prime.

It is a d-powerful number, because it can be written as 2¹⁴ + 4² + 8² + 6⁵ + 5⁴ .

It is a Duffinian number.

24865 is a lucky number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2482 + ... + 2491.

It is an arithmetic number, because the mean of its divisors is an integer number (7461).

2²⁴⁸⁶⁵ is an apocalyptic number.

24865 is the 112-nd centered square number.

It is an amenable number.

24865 is a deficient number, since it is larger than the sum of its proper divisors (4979).

24865 is an equidigital number, since it uses as much as digits as its factorization.

24865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4978.

The product of its digits is 1920, while the sum is 25.

The square root of 24865 is about 157.6863976378. The cubic root of 24865 is about 29.1874500394.

It can be divided in two parts, 248 and 65, that added together give a palindrome (313).

The spelling of 24865 in words is "twenty-four thousand, eight hundred sixty-five".