12391568667556 has 27 divisors (see below), whose sum is σ = 23481829447713. Its totient is φ = 5719143296880.

The previous prime is 12391568667551. The next prime is 12391568667581. The reversal of 12391568667556 is 65576686519321.

The square root of 12391568667556 is 3520166.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1833072288100 + 10558496379456 = 1353910^2 + 3249384^2 .

It is not an unprimeable number, because it can be changed into a prime (12391568667551) by changing a digit.

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 8 ways as a sum of consecutive naturals, for example, 91456621 + ... + 91592011.

Almost surely, 2^{12391568667556} is an apocalyptic number.

12391568667556 is the 3520166-th square number.

It is an amenable number.

12391568667556 is a deficient number, since it is larger than the sum of its proper divisors (11090260780157).

12391568667556 is an frugal number, since it uses more digits than its factorization.

12391568667556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270812 (or 135406 counting only the distinct ones).

The product of its digits is 489888000, while the sum is 70.

The spelling of 12391568667556 in words is "twelve trillion, three hundred ninety-one billion, five hundred sixty-eight million, six hundred sixty-seven thousand, five hundred fifty-six".