1278266443 has 2 divisors, whose sum is σ = 1278266444. Its totient is φ = 1278266442.

The previous prime is 1278266419. The next prime is 1278266449. The reversal of 1278266443 is 3446628721.

It is a strong prime.

It is an emirp because it is prime and its reverse (3446628721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1278266443 - 2⁵ = 1278266411 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1278266443.

It is not a weakly prime, because it can be changed into another prime (1278266449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639133221 + 639133222.

It is an arithmetic number, because the mean of its divisors is an integer number (639133222).

Almost surely, 2^1278266443 is an apocalyptic number.

1278266443 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278266443 is an equidigital number, since it uses as much as digits as its factorization.

1278266443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 43.

The square root of 1278266443 is about 35752.8522358706. The cubic root of 1278266443 is about 1085.2766587642.

The spelling of 1278266443 in words is "one billion, two hundred seventy-eight million, two hundred sixty-six thousand, four hundred forty-three".