12691478 has 4 divisors (see below), whose sum is σ = 19037220. Its totient is φ = 6345738.

The previous prime is 12691451. The next prime is 12691501. The reversal of 12691478 is 87419621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87419621 = 211 ⋅414311.

It is a super-2 number, since 2×12691478² = 322147227648968, which contains 22 as substring.

It is a Curzon number.

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, 3172868 + ... + 3172871.

It is an arithmetic number, because the mean of its divisors is an integer number (4759305).

Almost surely, 2^12691478 is an apocalyptic number.

12691478 is a deficient number, since it is larger than the sum of its proper divisors (6345742).

12691478 is an equidigital number, since it uses as much as digits as its factorization.

12691478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6345741.

The product of its digits is 24192, while the sum is 38.

The square root of 12691478 is about 3562.5100701612. The cubic root of 12691478 is about 233.2584580617.

The spelling of 12691478 in words is "twelve million, six hundred ninety-one thousand, four hundred seventy-eight".