12691284063978 has 16 divisors (see below), whose sum is σ = 27335073368736. Its totient is φ = 3905010481200.

The previous prime is 12691284063917. The next prime is 12691284063979. The reversal of 12691284063978 is 87936048219621.

It is a happy number.

It is a super-2 number, since 2×12691284063978² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12691284063979) 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, 81354384948 + ... + 81354385103.

It is an arithmetic number, because the mean of its divisors is an integer number (1708442085546).

Almost surely, 2^{12691284063978} is an apocalyptic number.

12691284063978 is an abundant number, since it is smaller than the sum of its proper divisors (14643789304758).

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

12691284063978 is a wasteful number, since it uses less digits than its factorization.

12691284063978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162708770069.

The product of its (nonzero) digits is 62705664, while the sum is 66.

The spelling of 12691284063978 in words is "twelve trillion, six hundred ninety-one billion, two hundred eighty-four million, sixty-three thousand, nine hundred seventy-eight".