1278427439 has 2 divisors, whose sum is σ = 1278427440. Its totient is φ = 1278427438.

The previous prime is 1278427393. The next prime is 1278427471. The reversal of 1278427439 is 9347248721.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1278427439 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1278427393 and 1278427402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278423439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639213719 + 639213720.

It is an arithmetic number, because the mean of its divisors is an integer number (639213720).

Almost surely, 2^1278427439 is an apocalyptic number.

1278427439 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278427439 is an equidigital number, since it uses as much as digits as its factorization.

1278427439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 677376, while the sum is 47.

The square root of 1278427439 is about 35755.1036776570. The cubic root of 1278427439 is about 1085.3222199138.

The spelling of 1278427439 in words is "one billion, two hundred seventy-eight million, four hundred twenty-seven thousand, four hundred thirty-nine".