12644645389 has 4 divisors (see below), whose sum is σ = 12760651420. Its totient is φ = 12528639360.

The previous prime is 12644645381. The next prime is 12644645413. The reversal of 12644645389 is 98354644621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98354644621 = 5059 ⋅19441519.

It can be written as a sum of positive squares in 2 ways, for example, as 3052010025 + 9592635364 = 55245^2 + 97942^2 .

It is a cyclic number.

It is not a de Polignac number, because 12644645389 - 2³ = 12644645381 is a prime.

It is a super-2 number, since 2×12644645389² (a number of 21 digits) 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 (12644645381) 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, 58002852 + ... + 58003069.

It is an arithmetic number, because the mean of its divisors is an integer number (3190162855).

Almost surely, 2^12644645389 is an apocalyptic number.

It is an amenable number.

12644645389 is a deficient number, since it is larger than the sum of its proper divisors (116006031).

12644645389 is a wasteful number, since it uses less digits than its factorization.

12644645389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116006030.

The product of its digits is 4976640, while the sum is 52.

The spelling of 12644645389 in words is "twelve billion, six hundred forty-four million, six hundred forty-five thousand, three hundred eighty-nine".