1287289 has 2 divisors, whose sum is σ = 1287290. Its totient is φ = 1287288.

The previous prime is 1287239. The next prime is 1287323. The reversal of 1287289 is 9827821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1283689 + 3600 = 1133^2 + 60^2 .

It is an emirp because it is prime and its reverse (9827821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1287289 - 2⁹ = 1286777 is a prime.

It is a super-2 number, since 2×1287289² = 3314225939042, which contains 22 as substring.

1287289 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1287239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643644 + 643645.

It is an arithmetic number, because the mean of its divisors is an integer number (643645).

2^1287289 is an apocalyptic number.

It is an amenable number.

1287289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287289 is an equidigital number, since it uses as much as digits as its factorization.

1287289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 37.

The square root of 1287289 is about 1134.5875902723. The cubic root of 1287289 is about 108.7824124992.

The spelling of 1287289 in words is "one million, two hundred eighty-seven thousand, two hundred eighty-nine".