18776839309 has 2 divisors, whose sum is σ = 18776839310. Its totient is φ = 18776839308.

The previous prime is 18776839271. The next prime is 18776839373. The reversal of 18776839309 is 90393867781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17009898084 + 1766941225 = 130422^2 + 42035^2 .

It is a cyclic number.

It is not a de Polignac number, because 18776839309 - 2⁷ = 18776839181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18776839399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9388419654 + 9388419655.

It is an arithmetic number, because the mean of its divisors is an integer number (9388419655).

Almost surely, 2^18776839309 is an apocalyptic number.

It is an amenable number.

18776839309 is a deficient number, since it is larger than the sum of its proper divisors (1).

18776839309 is an equidigital number, since it uses as much as digits as its factorization.

18776839309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13716864, while the sum is 61.

The spelling of 18776839309 in words is "eighteen billion, seven hundred seventy-six million, eight hundred thirty-nine thousand, three hundred nine".