12689861 has 4 divisors (see below), whose sum is σ = 12700512. Its totient is φ = 12679212.

The previous prime is 12689857. The next prime is 12689863. The reversal of 12689861 is 16898621.

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.

It is a cyclic number.

It is not a de Polignac number, because 12689861 - 2² = 12689857 is a prime.

It is a super-2 number, since 2×12689861² = 322065144398642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12689863) 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, 3275 + ... + 6008.

It is an arithmetic number, because the mean of its divisors is an integer number (3175128).

Almost surely, 2^12689861 is an apocalyptic number.

It is an amenable number.

12689861 is a deficient number, since it is larger than the sum of its proper divisors (10651).

12689861 is an equidigital number, since it uses as much as digits as its factorization.

12689861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10650.

The product of its digits is 41472, while the sum is 41.

The square root of 12689861 is about 3562.2831162051. The cubic root of 12689861 is about 233.2485512842.

It can be divided in two parts, 1 and 2689861, that added together give a palindrome (2689862).

The spelling of 12689861 in words is "twelve million, six hundred eighty-nine thousand, eight hundred sixty-one".