12978191 has 4 divisors (see below), whose sum is σ = 13741632. Its totient is φ = 12214752.

The previous prime is 12978169. The next prime is 12978211. The reversal of 12978191 is 19187921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19187921 = 59 ⋅325219.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12978191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12975191) 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, 381695 + ... + 381728.

It is an arithmetic number, because the mean of its divisors is an integer number (3435408).

Almost surely, 2^12978191 is an apocalyptic number.

12978191 is a deficient number, since it is larger than the sum of its proper divisors (763441).

12978191 is an equidigital number, since it uses as much as digits as its factorization.

12978191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 763440.

The product of its digits is 9072, while the sum is 38.

The square root of 12978191 is about 3602.5256418241. The cubic root of 12978191 is about 235.0019073332.

The spelling of 12978191 in words is "twelve million, nine hundred seventy-eight thousand, one hundred ninety-one".