12991939 has 2 divisors, whose sum is σ = 12991940. Its totient is φ = 12991938.

The previous prime is 12991931. The next prime is 12991967. The reversal of 12991939 is 93919921.

12991939 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12991939 - 2³ = 12991931 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12991895 and 12991904.

It is not a weakly prime, because it can be changed into another prime (12991931) 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, 6495969 + 6495970.

It is an arithmetic number, because the mean of its divisors is an integer number (6495970).

Almost surely, 2^12991939 is an apocalyptic number.

12991939 is a deficient number, since it is larger than the sum of its proper divisors (1).

12991939 is an equidigital number, since it uses as much as digits as its factorization.

12991939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39366, while the sum is 43.

The square root of 12991939 is about 3604.4332425501. The cubic root of 12991939 is about 235.0848584440.

The spelling of 12991939 in words is "twelve million, nine hundred ninety-one thousand, nine hundred thirty-nine".