1278349117 has 2 divisors, whose sum is σ = 1278349118. Its totient is φ = 1278349116.

The previous prime is 1278349091. The next prime is 1278349133. The reversal of 1278349117 is 7119438721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 805764996 + 472584121 = 28386^2 + 21739^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278349117 - 2¹⁵ = 1278316349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278349157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639174558 + 639174559.

It is an arithmetic number, because the mean of its divisors is an integer number (639174559).

Almost surely, 2^1278349117 is an apocalyptic number.

It is an amenable number.

1278349117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278349117 is an equidigital number, since it uses as much as digits as its factorization.

1278349117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 43.

The square root of 1278349117 is about 35754.0084046530. The cubic root of 1278349117 is about 1085.3000556151.

The spelling of 1278349117 in words is "one billion, two hundred seventy-eight million, three hundred forty-nine thousand, one hundred seventeen".