65805 has 16 divisors (see below), whose sum is σ = 108864. Its totient is φ = 33920.

The previous prime is 65789. The next prime is 65809. The reversal of 65805 is 50856.

65805 = T₃₀ + T₃₁ + ... + T₇₄.

It is not a de Polignac number, because 65805 - 2⁴ = 65789 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65809) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 562 + ... + 668.

It is an arithmetic number, because the mean of its divisors is an integer number (6804).

2⁶⁵⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

65805 is a deficient number, since it is larger than the sum of its proper divisors (43059).

65805 is a wasteful number, since it uses less digits than its factorization.

65805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 65805 is about 256.5248525972. The cubic root of 65805 is about 40.3725608536.

It can be divided in two parts, 65 and 805, that multiplied together give a palindrome (52325).

The spelling of 65805 in words is "sixty-five thousand, eight hundred five".