12644211665 has 8 divisors (see below), whose sum is σ = 15195273408. Its totient is φ = 10100556400.

The previous prime is 12644211661. The next prime is 12644211673. The reversal of 12644211665 is 56611244621.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12644211665 - 2² = 12644211661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12644211661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1847861 + ... + 1854690.

It is an arithmetic number, because the mean of its divisors is an integer number (1899409176).

Almost surely, 2^12644211665 is an apocalyptic number.

It is an amenable number.

12644211665 is a deficient number, since it is larger than the sum of its proper divisors (2551061743).

12644211665 is an equidigital number, since it uses as much as digits as its factorization.

12644211665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3703239.

The product of its digits is 69120, while the sum is 38.

The spelling of 12644211665 in words is "twelve billion, six hundred forty-four million, two hundred eleven thousand, six hundred sixty-five".