265805 has 4 divisors (see below), whose sum is σ = 318972. Its totient is φ = 212640.

The previous prime is 265787. The next prime is 265807. The reversal of 265805 is 508562.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 508562 = 2 ⋅254281.

It can be written as a sum of positive squares in 2 ways, for example, as 137641 + 128164 = 371^2 + 358^2 .

It is not a de Polignac number, because 265805 - 2¹⁴ = 249421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 265805.

It is not an unprimeable number, because it can be changed into a prime (265807) 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, 26576 + ... + 26585.

It is an arithmetic number, because the mean of its divisors is an integer number (79743).

2²⁶⁵⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

265805 is a deficient number, since it is larger than the sum of its proper divisors (53167).

265805 is an equidigital number, since it uses as much as digits as its factorization.

265805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53166.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 265805 is about 515.5627992786. The cubic root of 265805 is about 64.2965566662.

The spelling of 265805 in words is "two hundred sixty-five thousand, eight hundred five".