65665 has 8 divisors (see below), whose sum is σ = 82368. Its totient is φ = 50160.

The previous prime is 65657. The next prime is 65677. The reversal of 65665 is 56656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 65665 - 2³ = 65657 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171 + ... + 400.

It is an arithmetic number, because the mean of its divisors is an integer number (10296).

2⁶⁵⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

65665 is a deficient number, since it is larger than the sum of its proper divisors (16703).

65665 is a wasteful number, since it uses less digits than its factorization.

65665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599.

The product of its digits is 5400, while the sum is 28.

The square root of 65665 is about 256.2518292618. The cubic root of 65665 is about 40.3439096792.

Subtracting from 65665 its reverse (56656), we obtain a palindrome (9009).

It can be divided in two parts, 6 and 5665, that added together give a triangular number (5671 = T₁₀₆).

The spelling of 65665 in words is "sixty-five thousand, six hundred sixty-five".