20017687136809 has 2 divisors, whose sum is σ = 20017687136810. Its totient is φ = 20017687136808.

The previous prime is 20017687136747. The next prime is 20017687136827. The reversal of 20017687136809 is 90863178671002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16963459043584 + 3054228093225 = 4118672^2 + 1747635^2 .

It is a cyclic number.

It is not a de Polignac number, because 20017687136809 - 2³³ = 20009097202217 is a prime.

It is not a weakly prime, because it can be changed into another prime (20017687136849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10008843568404 + 10008843568405.

It is an arithmetic number, because the mean of its divisors is an integer number (10008843568405).

Almost surely, 2^{20017687136809} is an apocalyptic number.

It is an amenable number.

20017687136809 is a deficient number, since it is larger than the sum of its proper divisors (1).

20017687136809 is an equidigital number, since it uses as much as digits as its factorization.

20017687136809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6096384, while the sum is 58.

The spelling of 20017687136809 in words is "twenty trillion, seventeen billion, six hundred eighty-seven million, one hundred thirty-six thousand, eight hundred nine".