12659989 has 4 divisors (see below), whose sum is σ = 12670156. Its totient is φ = 12649824.

The previous prime is 12659963. The next prime is 12660013. The reversal of 12659989 is 98995621.

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: 98995621 = 2089 ⋅47389.

It can be written as a sum of positive squares in 2 ways, for example, as 12320100 + 339889 = 3510^2 + 583^2 .

It is a 3-Lehmer number, since φ(12659989) divides (12659989-1)³.

It is a cyclic number.

It is not a de Polignac number, because 12659989 - 2⁷ = 12659861 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 (12659389) 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, 2904 + ... + 5809.

It is an arithmetic number, because the mean of its divisors is an integer number (3167539).

It is a Poulet number, since it divides 2^12659988-1.

Almost surely, 2^12659989 is an apocalyptic number.

It is an amenable number.

12659989 is a deficient number, since it is larger than the sum of its proper divisors (10167).

12659989 is an equidigital number, since it uses as much as digits as its factorization.

12659989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10166.

The product of its digits is 349920, while the sum is 49.

The square root of 12659989 is about 3558.0878291577. The cubic root of 12659989 is about 233.0653847089.

The spelling of 12659989 in words is "twelve million, six hundred fifty-nine thousand, nine hundred eighty-nine".