12638378826 has 12 divisors (see below), whose sum is σ = 27383154162. Its totient is φ = 4212792936.

The previous prime is 12638378807. The next prime is 12638378839. The reversal of 12638378826 is 62887383621.

12638378826 is a `hidden beast` number, since 1 + 263 + 8 + 378 + 8 + 2 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 10424205801 + 2214173025 = 102099^2 + 47055^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 351066061 + ... + 351066096.

Almost surely, 2^12638378826 is an apocalyptic number.

12638378826 is an abundant number, since it is smaller than the sum of its proper divisors (14744775336).

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

12638378826 is a wasteful number, since it uses less digits than its factorization.

12638378826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 702132165 (or 702132162 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

It can be divided in two parts, 126383 and 78826, that added together give a square (205209 = 453²).

The spelling of 12638378826 in words is "twelve billion, six hundred thirty-eight million, three hundred seventy-eight thousand, eight hundred twenty-six".