12918643 has 4 divisors (see below), whose sum is σ = 12927040. Its totient is φ = 12910248.

The previous prime is 12918637. The next prime is 12918671. The reversal of 12918643 is 34681921.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 34681921 = 17 ⋅2040113.

It is a cyclic number.

It is not a de Polignac number, because 12918643 - 2⁹ = 12918131 is a prime.

It is a super-4 number, since 4×12918643⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12918599 and 12918608.

It is not an unprimeable number, because it can be changed into a prime (12918683) 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, 1155 + ... + 5212.

It is an arithmetic number, because the mean of its divisors is an integer number (3231760).

Almost surely, 2^12918643 is an apocalyptic number.

12918643 is a deficient number, since it is larger than the sum of its proper divisors (8397).

12918643 is an equidigital number, since it uses as much as digits as its factorization.

12918643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8396.

The product of its digits is 10368, while the sum is 34.

The square root of 12918643 is about 3594.2513824161. The cubic root of 12918643 is about 234.6419354622.

The spelling of 12918643 in words is "twelve million, nine hundred eighteen thousand, six hundred forty-three".