1289387273 has 2 divisors, whose sum is σ = 1289387274. Its totient is φ = 1289387272.

The previous prime is 1289387263. The next prime is 1289387279. The reversal of 1289387273 is 3727839821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1289384464 + 2809 = 35908^2 + 53^2 .

It is an emirp because it is prime and its reverse (3727839821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1289387273 - 2¹⁴ = 1289370889 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1289387279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644693636 + 644693637.

It is an arithmetic number, because the mean of its divisors is an integer number (644693637).

Almost surely, 2^1289387273 is an apocalyptic number.

It is an amenable number.

1289387273 is a deficient number, since it is larger than the sum of its proper divisors (1).

1289387273 is an equidigital number, since it uses as much as digits as its factorization.

1289387273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 50.

The square root of 1289387273 is about 35908.0391138252. The cubic root of 1289387273 is about 1088.4148529818.

The spelling of 1289387273 in words is "one billion, two hundred eighty-nine million, three hundred eighty-seven thousand, two hundred seventy-three".