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1289 is a prime number

1289 has 2 divisors, whose sum is σ = 1290. Its totient is φ = 1288.

The previous prime is 1283. The next prime is 1291. The reversal of 1289 is 9821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1225 + 64 = 35^2 + 8^2 .

It is a cyclic number.

It is not a de Polignac number, because 1289 - 28 = 1033 is a prime.

It is a Sophie Germain prime.

Together with 1291, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 10 and base 15.

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 1289.

It is not a weakly prime, because it can be changed into another prime (1283) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644 + 645.

It is an arithmetic number, because the mean of its divisors is an integer number (645).

21289 is an apocalyptic number.

It is an amenable number.

1289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1289 is an equidigital number, since it uses as much as digits as its factorization.

1289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 20.

The square root of 1289 is about 35.9026461420. The cubic root of 1289 is about 10.8830587205.

It can be divided in two parts, 12 and 89, that added together give a palindrome (101).

The spelling of 1289 in words is "one thousand, two hundred eighty-nine".