1321765 has 4 divisors (see below), whose sum is σ = 1586124. Its totient is φ = 1057408.

The previous prime is 1321763. The next prime is 1321769. The reversal of 1321765 is 5671231.

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 954529 + 367236 = 977^2 + 606^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321765 - 2¹ = 1321763 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321763) 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, 132172 + ... + 132181.

It is an arithmetic number, because the mean of its divisors is an integer number (396531).

2^1321765 is an apocalyptic number.

It is an amenable number.

1321765 is a deficient number, since it is larger than the sum of its proper divisors (264359).

1321765 is an equidigital number, since it uses as much as digits as its factorization.

1321765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264358.

The product of its digits is 1260, while the sum is 25.

The square root of 1321765 is about 1149.6803903694. The cubic root of 1321765 is about 109.7450016144.

Adding to 1321765 its reverse (5671231), we get a palindrome (6992996).

The spelling of 1321765 in words is "one million, three hundred twenty-one thousand, seven hundred sixty-five".