12991869 has 12 divisors (see below), whose sum is σ = 20472192. Its totient is φ = 7873800.

The previous prime is 12991813. The next prime is 12991871. The reversal of 12991869 is 96819921.

It is not a de Polignac number, because 12991869 - 2⁸ = 12991613 is a prime.

It is a super-2 number, since 2×12991869² = 337577320226322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12991879) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65517 + ... + 65714.

It is an arithmetic number, because the mean of its divisors is an integer number (1706016).

Almost surely, 2^12991869 is an apocalyptic number.

It is an amenable number.

12991869 is a deficient number, since it is larger than the sum of its proper divisors (7480323).

12991869 is a wasteful number, since it uses less digits than its factorization.

12991869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131248 (or 131245 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 12991869 is about 3604.4235322725. The cubic root of 12991869 is about 235.0844362343.

The spelling of 12991869 in words is "twelve million, nine hundred ninety-one thousand, eight hundred sixty-nine".