1320289 has 4 divisors (see below), whose sum is σ = 1329300. Its totient is φ = 1311280.

The previous prime is 1320287. The next prime is 1320301. The reversal of 1320289 is 9820231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9820231 = 743 ⋅13217.

It can be written as a sum of positive squares in 2 ways, for example, as 819025 + 501264 = 905^2 + 708^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320289 - 2¹ = 1320287 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1320287) 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, 4282 + ... + 4579.

It is an arithmetic number, because the mean of its divisors is an integer number (332325).

2^1320289 is an apocalyptic number.

It is an amenable number.

1320289 is a deficient number, since it is larger than the sum of its proper divisors (9011).

1320289 is an equidigital number, since it uses as much as digits as its factorization.

1320289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9010.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1320289 is about 1149.0382935307. The cubic root of 1320289 is about 109.7041360660.

It can be divided in two parts, 13 and 20289, that added together give a palindrome (20302).

The spelling of 1320289 in words is "one million, three hundred twenty thousand, two hundred eighty-nine".