12644503605 has 24 divisors (see below), whose sum is σ = 22134148920. Its totient is φ = 6676963200.

The previous prime is 12644503601. The next prime is 12644503633. The reversal of 12644503605 is 50630544621.

12644503605 is a `hidden beast` number, since 1 + 2 + 6 + 4 + 45 + 0 + 3 + 605 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4620464676 + 8024038929 = 67974^2 + 89577^2 .

It is not a de Polignac number, because 12644503605 - 2² = 12644503601 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12644503605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12644503601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1386490 + ... + 1395579.

It is an arithmetic number, because the mean of its divisors is an integer number (922256205).

Almost surely, 2^12644503605 is an apocalyptic number.

12644503605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12644503605 is a deficient number, since it is larger than the sum of its proper divisors (9489645315).

12644503605 is a wasteful number, since it uses less digits than its factorization.

12644503605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2782181 (or 2782178 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The spelling of 12644503605 in words is "twelve billion, six hundred forty-four million, five hundred three thousand, six hundred five".