12991338 has 24 divisors (see below), whose sum is σ = 28374528. Its totient is φ = 4295592.

The previous prime is 12991331. The next prime is 12991339. The reversal of 12991338 is 83319921.

It is not an unprimeable number, because it can be changed into a prime (12991331) 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 11 ways as a sum of consecutive naturals, for example, 556 + ... + 5127.

It is an arithmetic number, because the mean of its divisors is an integer number (1182272).

Almost surely, 2^12991338 is an apocalyptic number.

12991338 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12991338 is an abundant number, since it is smaller than the sum of its proper divisors (15383190).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12991338 is a wasteful number, since it uses less digits than its factorization.

12991338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5818 (or 5815 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 12991338 is about 3604.3498720296. The cubic root of 12991338 is about 235.0812334224.

The spelling of 12991338 in words is "twelve million, nine hundred ninety-one thousand, three hundred thirty-eight".