18778057189 has 2 divisors, whose sum is σ = 18778057190. Its totient is φ = 18778057188.

The previous prime is 18778057171. The next prime is 18778057229. The reversal of 18778057189 is 98175087781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14426412100 + 4351645089 = 120110^2 + 65967^2 .

It is a cyclic number.

It is not a de Polignac number, because 18778057189 - 2¹³ = 18778048997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18778057889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9389028594 + 9389028595.

It is an arithmetic number, because the mean of its divisors is an integer number (9389028595).

Almost surely, 2^18778057189 is an apocalyptic number.

It is an amenable number.

18778057189 is a deficient number, since it is larger than the sum of its proper divisors (1).

18778057189 is an equidigital number, since it uses as much as digits as its factorization.

18778057189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7902720, while the sum is 61.

The spelling of 18778057189 in words is "eighteen billion, seven hundred seventy-eight million, fifty-seven thousand, one hundred eighty-nine".