12979861 has 4 divisors (see below), whose sum is σ = 13113772. Its totient is φ = 12845952.

The previous prime is 12979847. The next prime is 12979877. The reversal of 12979861 is 16897921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16897921 = 2089 ⋅8089.

It can be written as a sum of positive squares in 2 ways, for example, as 2579236 + 10400625 = 1606^2 + 3225^2 .

It is a cyclic number.

It is not a de Polignac number, because 12979861 - 2¹¹ = 12977813 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 (12979801) 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, 66810 + ... + 67003.

It is an arithmetic number, because the mean of its divisors is an integer number (3278443).

Almost surely, 2^12979861 is an apocalyptic number.

It is an amenable number.

12979861 is a deficient number, since it is larger than the sum of its proper divisors (133911).

12979861 is an equidigital number, since it uses as much as digits as its factorization.

12979861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133910.

The product of its digits is 54432, while the sum is 43.

The square root of 12979861 is about 3602.7574162022. The cubic root of 12979861 is about 235.0119867132.

The spelling of 12979861 in words is "twelve million, nine hundred seventy-nine thousand, eight hundred sixty-one".