12665504640 has 64 divisors (see below), whose sum is σ = 40371302160. Its totient is φ = 3377467392.

The previous prime is 12665504629. The next prime is 12665504647. The reversal of 12665504640 is 4640556621.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12665504647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3296389 + ... + 3300228.

Almost surely, 2^12665504640 is an apocalyptic number.

12665504640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12665504640 is an abundant number, since it is smaller than the sum of its proper divisors (27705797520).

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

12665504640 is an equidigital number, since it uses as much as digits as its factorization.

12665504640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6596639 (or 6596627 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 39.

The spelling of 12665504640 in words is "twelve billion, six hundred sixty-five million, five hundred four thousand, six hundred forty".