12991913 has 16 divisors (see below), whose sum is σ = 14817600. Its totient is φ = 11282880.

The previous prime is 12991879. The next prime is 12991931. The reversal of 12991913 is 31919921.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12991913 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12991513) 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 in 15 ways as a sum of consecutive naturals, for example, 44195 + ... + 44487.

It is an arithmetic number, because the mean of its divisors is an integer number (926100).

Almost surely, 2^12991913 is an apocalyptic number.

It is an amenable number.

12991913 is a deficient number, since it is larger than the sum of its proper divisors (1825687).

12991913 is a wasteful number, since it uses less digits than its factorization.

12991913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472.

The product of its digits is 4374, while the sum is 35.

The square root of 12991913 is about 3604.4296358786. The cubic root of 12991913 is about 235.0847016234.

The spelling of 12991913 in words is "twelve million, nine hundred ninety-one thousand, nine hundred thirteen".