12991603 has 2 divisors, whose sum is σ = 12991604. Its totient is φ = 12991602.

The previous prime is 12991571. The next prime is 12991609. The reversal of 12991603 is 30619921.

It is a strong prime.

It is an emirp because it is prime and its reverse (30619921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12991603 - 2⁵ = 12991571 is a prime.

It is a zygodrome in base 2.

It is not a weakly prime, because it can be changed into another prime (12991609) 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, 6495801 + 6495802.

It is an arithmetic number, because the mean of its divisors is an integer number (6495802).

Almost surely, 2^12991603 is an apocalyptic number.

12991603 is a deficient number, since it is larger than the sum of its proper divisors (1).

12991603 is an equidigital number, since it uses as much as digits as its factorization.

12991603 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 12991603 is about 3604.3866329793. The cubic root of 12991603 is about 235.0828318234.

The spelling of 12991603 in words is "twelve million, nine hundred ninety-one thousand, six hundred three".