1278439 has 2 divisors, whose sum is σ = 1278440. Its totient is φ = 1278438.

The previous prime is 1278437. The next prime is 1278463. The reversal of 1278439 is 9348721.

It is a weak prime.

It is an emirp because it is prime and its reverse (9348721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1278439 - 2¹ = 1278437 is a prime.

Together with 1278437, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639219 + 639220.

It is an arithmetic number, because the mean of its divisors is an integer number (639220).

2^1278439 is an apocalyptic number.

1278439 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278439 is an equidigital number, since it uses as much as digits as its factorization.

1278439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 1278439 is about 1130.6807683869. The cubic root of 1278439 is about 108.5325491478.

The spelling of 1278439 in words is "one million, two hundred seventy-eight thousand, four hundred thirty-nine".