12697891 has 4 divisors (see below), whose sum is σ = 12705784. Its totient is φ = 12690000.

The previous prime is 12697859. The next prime is 12697901. The reversal of 12697891 is 19879621.

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, and also an emirpimes, since its reverse is a distinct semiprime: 19879621 = 547 ⋅36343.

It is a cyclic number.

It is not a de Polignac number, because 12697891 - 2⁵ = 12697859 is a prime.

It is a super-2 number, since 2×12697891² = 322472871695762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12691891) 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, 570 + ... + 5071.

It is an arithmetic number, because the mean of its divisors is an integer number (3176446).

Almost surely, 2^12697891 is an apocalyptic number.

12697891 is a deficient number, since it is larger than the sum of its proper divisors (7893).

12697891 is an equidigital number, since it uses as much as digits as its factorization.

12697891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7892.

The product of its digits is 54432, while the sum is 43.

The square root of 12697891 is about 3563.4100241202. The cubic root of 12697891 is about 233.2977399222.

The spelling of 12697891 in words is "twelve million, six hundred ninety-seven thousand, eight hundred ninety-one".