12991039 has 4 divisors (see below), whose sum is σ = 13001560. Its totient is φ = 12980520.

The previous prime is 12991037. The next prime is 12991049. The reversal of 12991039 is 93019921.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 12991039 - 2¹ = 12991037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12990995 and 12991013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12991037) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3117 + ... + 5974.

It is an arithmetic number, because the mean of its divisors is an integer number (3250390).

Almost surely, 2^12991039 is an apocalyptic number.

12991039 is a deficient number, since it is larger than the sum of its proper divisors (10521).

12991039 is an equidigital number, since it uses as much as digits as its factorization.

12991039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10520.

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 12991039 is about 3604.3083941306. The cubic root of 12991039 is about 235.0794299175.

The spelling of 12991039 in words is "twelve million, nine hundred ninety-one thousand, thirty-nine".