1278170791 has 2 divisors, whose sum is σ = 1278170792. Its totient is φ = 1278170790.

The previous prime is 1278170779. The next prime is 1278170821. The reversal of 1278170791 is 1970718721.

It is a weak prime.

It is an emirp because it is prime and its reverse (1970718721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1278170791 - 2²⁹ = 741299879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278170731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639085395 + 639085396.

It is an arithmetic number, because the mean of its divisors is an integer number (639085396).

Almost surely, 2^1278170791 is an apocalyptic number.

1278170791 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278170791 is an equidigital number, since it uses as much as digits as its factorization.

1278170791 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 49392, while the sum is 43.

The square root of 1278170791 is about 35751.5145273595. The cubic root of 1278170791 is about 1085.2495878633.

The spelling of 1278170791 in words is "one billion, two hundred seventy-eight million, one hundred seventy thousand, seven hundred ninety-one".