12666537440 has 24 divisors (see below), whose sum is σ = 29924695080. Its totient is φ = 5066614912.

The previous prime is 12666537427. The next prime is 12666537479. The reversal of 12666537440 is 4473566621.

12666537440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 12666537391 and 12666537400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39582770 + ... + 39583089.

It is an arithmetic number, because the mean of its divisors is an integer number (1246862295).

Almost surely, 2^12666537440 is an apocalyptic number.

12666537440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12666537440 is an abundant number, since it is smaller than the sum of its proper divisors (17258157640).

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

12666537440 is an equidigital number, since it uses as much as digits as its factorization.

12666537440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79165874 (or 79165866 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 44.

The spelling of 12666537440 in words is "twelve billion, six hundred sixty-six million, five hundred thirty-seven thousand, four hundred forty".