12778013865 has 32 divisors (see below), whose sum is σ = 20700408960. Its totient is φ = 6730159104.

The previous prime is 12778013863. The next prime is 12778013873. The reversal of 12778013865 is 56831087721.

It is a happy number.

It is not a de Polignac number, because 12778013865 - 2¹ = 12778013863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12778013863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 489217 + ... + 514673.

It is an arithmetic number, because the mean of its divisors is an integer number (646887780).

Almost surely, 2^12778013865 is an apocalyptic number.

12778013865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12778013865 is a deficient number, since it is larger than the sum of its proper divisors (7922395095).

12778013865 is a wasteful number, since it uses less digits than its factorization.

12778013865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25881.

The product of its (nonzero) digits is 564480, while the sum is 48.

The spelling of 12778013865 in words is "twelve billion, seven hundred seventy-eight million, thirteen thousand, eight hundred sixty-five".