12665380644 has 300 divisors, whose sum is σ = 39363640624. Its totient is φ = 3564670032.

The previous prime is 12665380621. The next prime is 12665380697. The reversal of 12665380644 is 44608356621.

12665380644 is a `hidden beast` number, since 1 + 266 + 5 + 380 + 6 + 4 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 12665380644.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 99 ways as a sum of consecutive naturals, for example, 189035499 + ... + 189035565.

Almost surely, 2^12665380644 is an apocalyptic number.

12665380644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12665380644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19681820312).

12665380644 is an abundant number, since it is smaller than the sum of its proper divisors (26698259980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12665380644 is an frugal number, since it uses more digits than its factorization.

12665380644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 12665380644 in words is "twelve billion, six hundred sixty-five million, three hundred eighty thousand, six hundred forty-four".