18778849049 has 2 divisors, whose sum is σ = 18778849050. Its totient is φ = 18778849048.

The previous prime is 18778849027. The next prime is 18778849121. The reversal of 18778849049 is 94094887781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16181112025 + 2597737024 = 127205^2 + 50968^2 .

It is a cyclic number.

It is not a de Polignac number, because 18778849049 - 2²⁴ = 18762071833 is a prime.

It is not a weakly prime, because it can be changed into another prime (18778849949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9389424524 + 9389424525.

It is an arithmetic number, because the mean of its divisors is an integer number (9389424525).

Almost surely, 2^18778849049 is an apocalyptic number.

It is an amenable number.

18778849049 is a deficient number, since it is larger than the sum of its proper divisors (1).

18778849049 is an equidigital number, since it uses as much as digits as its factorization.

18778849049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32514048, while the sum is 65.

The spelling of 18778849049 in words is "eighteen billion, seven hundred seventy-eight million, eight hundred forty-nine thousand, forty-nine".