12978869 has 4 divisors (see below), whose sum is σ = 12987744. Its totient is φ = 12969996.

The previous prime is 12978859. The next prime is 12978883. The reversal of 12978869 is 96887921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 96887921 = 13 ⋅7452917.

It is a cyclic number.

It is not a de Polignac number, because 12978869 - 2⁴ = 12978853 is a prime.

It is a super-2 number, since 2×12978869² = 336902081038322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12978809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1667 + ... + 5360.

It is an arithmetic number, because the mean of its divisors is an integer number (3246936).

Almost surely, 2^12978869 is an apocalyptic number.

It is an amenable number.

12978869 is a deficient number, since it is larger than the sum of its proper divisors (8875).

12978869 is an equidigital number, since it uses as much as digits as its factorization.

12978869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8874.

The product of its digits is 435456, while the sum is 50.

The square root of 12978869 is about 3602.6197412439. The cubic root of 12978869 is about 235.0059995450.

The spelling of 12978869 in words is "twelve million, nine hundred seventy-eight thousand, eight hundred sixty-nine".