138764778408 has 48 divisors (see below), whose sum is σ = 397928412180. Its totient is φ = 43534047744.

The previous prime is 138764778401. The next prime is 138764778409. The reversal of 138764778408 is 804877467831.

138764778408 is a `hidden beast` number, since 1 + 3 + 87 + 6 + 477 + 84 + 0 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 138549217284 + 215561124 = 372222^2 + 14682^2 .

It is not an unprimeable number, because it can be changed into a prime (138764778401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56683735 + ... + 56686182.

Almost surely, 2^138764778408 is an apocalyptic number.

138764778408 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138764778408 is an abundant number, since it is smaller than the sum of its proper divisors (259163633772).

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

138764778408 is a wasteful number, since it uses less digits than its factorization.

138764778408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113369946 (or 113369939 counting only the distinct ones).

The product of its (nonzero) digits is 50577408, while the sum is 63.

The spelling of 138764778408 in words is "one hundred thirty-eight billion, seven hundred sixty-four million, seven hundred seventy-eight thousand, four hundred eight".