12644031667 has 4 divisors (see below), whose sum is σ = 12766789360. Its totient is φ = 12521273976.

The previous prime is 12644031643. The next prime is 12644031671. The reversal of 12644031667 is 76613044621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12644031667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12644031637) 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, 61378692 + ... + 61378897.

It is an arithmetic number, because the mean of its divisors is an integer number (3191697340).

Almost surely, 2^12644031667 is an apocalyptic number.

12644031667 is a deficient number, since it is larger than the sum of its proper divisors (122757693).

12644031667 is a wasteful number, since it uses less digits than its factorization.

12644031667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122757692.

The product of its (nonzero) digits is 145152, while the sum is 40.

The spelling of 12644031667 in words is "twelve billion, six hundred forty-four million, thirty-one thousand, six hundred sixty-seven".