1321565 has 16 divisors (see below), whose sum is σ = 1845120. Its totient is φ = 889920.

The previous prime is 1321549. The next prime is 1321571. The reversal of 1321565 is 5651231.

It is not a de Polignac number, because 1321565 - 2⁴ = 1321549 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321565.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1826 + ... + 2444.

It is an arithmetic number, because the mean of its divisors is an integer number (115320).

2^1321565 is an apocalyptic number.

It is an amenable number.

1321565 is a deficient number, since it is larger than the sum of its proper divisors (523555).

1321565 is an equidigital number, since it uses as much as digits as its factorization.

1321565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692.

The product of its digits is 900, while the sum is 23.

The square root of 1321565 is about 1149.5934063833. The cubic root of 1321565 is about 109.7394660597.

Adding to 1321565 its reverse (5651231), we get a palindrome (6972796).

The spelling of 1321565 in words is "one million, three hundred twenty-one thousand, five hundred sixty-five".