12691678 has 4 divisors (see below), whose sum is σ = 19037520. Its totient is φ = 6345838.

The previous prime is 12691649. The next prime is 12691691. The reversal of 12691678 is 87619621.

12691678 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×12691678² = 322157380911368, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 12691678.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3172918 + ... + 3172921.

It is an arithmetic number, because the mean of its divisors is an integer number (4759380).

Almost surely, 2^12691678 is an apocalyptic number.

12691678 is a deficient number, since it is larger than the sum of its proper divisors (6345842).

12691678 is an equidigital number, since it uses as much as digits as its factorization.

12691678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6345841.

The product of its digits is 36288, while the sum is 40.

The square root of 12691678 is about 3562.5381401467. The cubic root of 12691678 is about 233.2596833313.

The spelling of 12691678 in words is "twelve million, six hundred ninety-one thousand, six hundred seventy-eight".