1321289 has 2 divisors, whose sum is σ = 1321290. Its totient is φ = 1321288.

The previous prime is 1321283. The next prime is 1321301. The reversal of 1321289 is 9821231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 795664 + 525625 = 892^2 + 725^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321289 - 2⁴ = 1321273 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1321283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660644 + 660645.

It is an arithmetic number, because the mean of its divisors is an integer number (660645).

2^1321289 is an apocalyptic number.

It is an amenable number.

1321289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321289 is an equidigital number, since it uses as much as digits as its factorization.

1321289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 26.

The square root of 1321289 is about 1149.4733576730. The cubic root of 1321289 is about 109.7318260769.

The spelling of 1321289 in words is "one million, three hundred twenty-one thousand, two hundred eighty-nine".