12861756378 has 12 divisors (see below), whose sum is σ = 27867138858. Its totient is φ = 4287252120.

The previous prime is 12861756367. The next prime is 12861756407. The reversal of 12861756378 is 87365716821.

It is a happy number.

12861756378 is a `hidden beast` number, since 1 + 2 + 8 + 6 + 1 + 7 + 563 + 78 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11348001729 + 1513754649 = 106527^2 + 38907^2 .

It is a Curzon 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 in 5 ways as a sum of consecutive naturals, for example, 357270993 + ... + 357271028.

Almost surely, 2^12861756378 is an apocalyptic number.

12861756378 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12861756378 is an abundant number, since it is smaller than the sum of its proper divisors (15005382480).

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

12861756378 is a wasteful number, since it uses less digits than its factorization.

12861756378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 714542029 (or 714542026 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The spelling of 12861756378 in words is "twelve billion, eight hundred sixty-one million, seven hundred fifty-six thousand, three hundred seventy-eight".