1281439 has 2 divisors, whose sum is σ = 1281440. Its totient is φ = 1281438.

The previous prime is 1281433. The next prime is 1281451. The reversal of 1281439 is 9341821.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (9341821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1281439 - 2³ = 1281431 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1281431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640719 + 640720.

It is an arithmetic number, because the mean of its divisors is an integer number (640720).

2^1281439 is an apocalyptic number.

1281439 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281439 is an equidigital number, since it uses as much as digits as its factorization.

1281439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 28.

The square root of 1281439 is about 1132.0066254223. The cubic root of 1281439 is about 108.6173774150.

The spelling of 1281439 in words is "one million, two hundred eighty-one thousand, four hundred thirty-nine".