138405937856 has 28 divisors (see below), whose sum is σ = 286590559152. Its totient is φ = 66194143488.

The previous prime is 138405937843. The next prime is 138405937867. The reversal of 138405937856 is 658739504831.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 138405937795 and 138405937804.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47011415 + ... + 47014358.

Almost surely, 2^138405937856 is an apocalyptic number.

138405937856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

138405937856 is an abundant number, since it is smaller than the sum of its proper divisors (148184621296).

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

138405937856 is an equidigital number, since it uses as much as digits as its factorization.

138405937856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94025808 (or 94025798 counting only the distinct ones).

The product of its (nonzero) digits is 21772800, while the sum is 59.

The spelling of 138405937856 in words is "one hundred thirty-eight billion, four hundred five million, nine hundred thirty-seven thousand, eight hundred fifty-six".