1278376139 has 2 divisors, whose sum is σ = 1278376140. Its totient is φ = 1278376138.

The previous prime is 1278376129. The next prime is 1278376163. The reversal of 1278376139 is 9316738721.

It is a weak prime.

It is an emirp because it is prime and its reverse (9316738721) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1278376139 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1278376093 and 1278376102.

It is not a weakly prime, because it can be changed into another prime (1278376129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639188069 + 639188070.

It is an arithmetic number, because the mean of its divisors is an integer number (639188070).

Almost surely, 2^1278376139 is an apocalyptic number.

1278376139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278376139 is an equidigital number, since it uses as much as digits as its factorization.

1278376139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 381024, while the sum is 47.

The square root of 1278376139 is about 35754.3862903560. The cubic root of 1278376139 is about 1085.3077026579.

The spelling of 1278376139 in words is "one billion, two hundred seventy-eight million, three hundred seventy-six thousand, one hundred thirty-nine".