1205565 has 16 divisors (see below), whose sum is σ = 1944000. Its totient is φ = 637952.

The previous prime is 1205563. The next prime is 1205609. The reversal of 1205565 is 5655021.

It is a cyclic number.

It is not a de Polignac number, because 1205565 - 2¹ = 1205563 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 (1205563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2461 + ... + 2909.

It is an arithmetic number, because the mean of its divisors is an integer number (121500).

2^1205565 is an apocalyptic number.

1205565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1205565 is a deficient number, since it is larger than the sum of its proper divisors (738435).

1205565 is a wasteful number, since it uses less digits than its factorization.

1205565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636.

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 1205565 is about 1097.9822402935. The cubic root of 1205565 is about 106.4298729413.

It can be divided in two parts, 1205 and 565, that added together give a triangular number (1770 = T₅₉).

The spelling of 1205565 in words is "one million, two hundred five thousand, five hundred sixty-five".