1278427393 has 2 divisors, whose sum is σ = 1278427394. Its totient is φ = 1278427392.

The previous prime is 1278427379. The next prime is 1278427439. The reversal of 1278427393 is 3937248721.

It is an a-pointer prime, because the next prime (1278427439) can be obtained adding 1278427393 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 913731984 + 364695409 = 30228^2 + 19097^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278427393 - 2²⁵ = 1244872961 is a prime.

It is not a weakly prime, because it can be changed into another prime (1278427303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639213696 + 639213697.

It is an arithmetic number, because the mean of its divisors is an integer number (639213697).

Almost surely, 2^1278427393 is an apocalyptic number.

It is an amenable number.

1278427393 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278427393 is an equidigital number, since it uses as much as digits as its factorization.

1278427393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 46.

The square root of 1278427393 is about 35755.1030343922. The cubic root of 1278427393 is about 1085.3222068965.

The spelling of 1278427393 in words is "one billion, two hundred seventy-eight million, four hundred twenty-seven thousand, three hundred ninety-three".