1278170549 has 2 divisors, whose sum is σ = 1278170550. Its totient is φ = 1278170548.

The previous prime is 1278170539. The next prime is 1278170557. The reversal of 1278170549 is 9450718721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1121044324 + 157126225 = 33482^2 + 12535^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278170549 - 2⁸ = 1278170293 is a prime.

It is a super-2 number, since 2×1278170549² = 3267439904661922802, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278170519) 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, 639085274 + 639085275.

It is an arithmetic number, because the mean of its divisors is an integer number (639085275).

Almost surely, 2^1278170549 is an apocalyptic number.

It is an amenable number.

1278170549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278170549 is an equidigital number, since it uses as much as digits as its factorization.

1278170549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 141120, while the sum is 44.

The square root of 1278170549 is about 35751.5111428874. The cubic root of 1278170549 is about 1085.2495193721.

The spelling of 1278170549 in words is "one billion, two hundred seventy-eight million, one hundred seventy thousand, five hundred forty-nine".