12644843531 has 4 divisors (see below), whose sum is σ = 12709030752. Its totient is φ = 12580656312.

The previous prime is 12644843527. The next prime is 12644843543. The reversal of 12644843531 is 13534844621.

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

It is a cyclic number.

It is not a de Polignac number, because 12644843531 - 2² = 12644843527 is a prime.

It is a super-2 number, since 2×12644843531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12644843521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32093315 + ... + 32093708.

It is an arithmetic number, because the mean of its divisors is an integer number (3177257688).

Almost surely, 2^12644843531 is an apocalyptic number.

12644843531 is a deficient number, since it is larger than the sum of its proper divisors (64187221).

12644843531 is an equidigital number, since it uses as much as digits as its factorization.

12644843531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64187220.

The product of its digits is 276480, while the sum is 41.

The spelling of 12644843531 in words is "twelve billion, six hundred forty-four million, eight hundred forty-three thousand, five hundred thirty-one".