12781939 has 2 divisors, whose sum is σ = 12781940. Its totient is φ = 12781938.

The previous prime is 12781931. The next prime is 12782009. The reversal of 12781939 is 93918721.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12781939 - 2³ = 12781931 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12781931) 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, 6390969 + 6390970.

It is an arithmetic number, because the mean of its divisors is an integer number (6390970).

Almost surely, 2^12781939 is an apocalyptic number.

12781939 is a deficient number, since it is larger than the sum of its proper divisors (1).

12781939 is an equidigital number, since it uses as much as digits as its factorization.

12781939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 40.

The square root of 12781939 is about 3575.1837715004. The cubic root of 12781939 is about 233.8113450096.

The spelling of 12781939 in words is "twelve million, seven hundred eighty-one thousand, nine hundred thirty-nine".