12651687778766 has 4 divisors (see below), whose sum is σ = 18977531668152. Its totient is φ = 6325843889382.

The previous prime is 12651687778729. The next prime is 12651687778799. The reversal of 12651687778766 is 66787778615621.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3162921944690 + ... + 3162921944693.

It is an arithmetic number, because the mean of its divisors is an integer number (4744382917038).

Almost surely, 2^{12651687778766} is an apocalyptic number.

12651687778766 is a deficient number, since it is larger than the sum of its proper divisors (6325843889386).

12651687778766 is an equidigital number, since it uses as much as digits as its factorization.

12651687778766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6325843889385.

The product of its digits is 1991485440, while the sum is 77.

The spelling of 12651687778766 in words is "twelve trillion, six hundred fifty-one billion, six hundred eighty-seven million, seven hundred seventy-eight thousand, seven hundred sixty-six".