18939555385178 has 16 divisors (see below), whose sum is σ = 28419902745000. Its totient is φ = 9466254749952.

The previous prime is 18939555385073. The next prime is 18939555385187. The reversal of 18939555385178 is 87158355593981.

It can be written as a sum of positive squares in 4 ways, for example, as 5808085540009 + 13131469845169 = 2409997^2 + 3623737^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18939555385099 and 18939555385108.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175135388 + ... + 175243496.

Almost surely, 2^{18939555385178} is an apocalyptic number.

18939555385178 is a deficient number, since it is larger than the sum of its proper divisors (9480347359822).

18939555385178 is a wasteful number, since it uses less digits than its factorization.

18939555385178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139889.

The product of its digits is 1632960000, while the sum is 77.

The spelling of 18939555385178 in words is "eighteen trillion, nine hundred thirty-nine billion, five hundred fifty-five million, three hundred eighty-five thousand, one hundred seventy-eight".