12978911 has 4 divisors (see below), whose sum is σ = 14158824. Its totient is φ = 11799000.

The previous prime is 12978899. The next prime is 12978913. The reversal of 12978911 is 11987921.

12978911 is digitally balanced in base 3, 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 cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12978911 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 (12978913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 589940 + ... + 589961.

It is an arithmetic number, because the mean of its divisors is an integer number (3539706).

Almost surely, 2^12978911 is an apocalyptic number.

12978911 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12978911 is a deficient number, since it is larger than the sum of its proper divisors (1179913).

12978911 is a wasteful number, since it uses less digits than its factorization.

12978911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1179912.

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

The square root of 12978911 is about 3602.6255703306. The cubic root of 12978911 is about 235.0062530402.

The spelling of 12978911 in words is "twelve million, nine hundred seventy-eight thousand, nine hundred eleven".