565 has 4 divisors (see below), whose sum is σ = 684. Its totient is φ = 448.

The previous prime is 563. The next prime is 569.

It is a happy number.

565 is nontrivially palindromic in base 10 and base 11.

565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

565 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 81 + 484 = 9^2 + 22^2 .

It is a cyclic number.

It is not a de Polignac number, because 565 - 2¹ = 563 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

565 is an undulating number in base 10 and base 11.

It is a plaindrome in base 13, base 15 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (563) 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 3 ways as a sum of consecutive naturals, for example, 52 + ... + 61.

It is an arithmetic number, because the mean of its divisors is an integer number (171).

It is an amenable number.

565 is a deficient number, since it is larger than the sum of its proper divisors (119).

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

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

The sum of its prime factors is 118.

The product of its digits is 150, while the sum is 16.

The square root of 565 is about 23.7697286480. The cubic root of 565 is about 8.2670294094.

It can be divided in two parts, 5 and 65, that multiplied together give a triangular number (325 = T₂₅).

The spelling of 565 in words is "five hundred sixty-five", and thus it is an aban number and an oban number.