20128737648809 has 2 divisors, whose sum is σ = 20128737648810. Its totient is φ = 20128737648808.

The previous prime is 20128737648707. The next prime is 20128737648947. The reversal of 20128737648809 is 90884673782102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19309345177600 + 819392471209 = 4394240^2 + 905203^2 .

It is a cyclic number.

It is not a de Polignac number, because 20128737648809 - 2¹² = 20128737644713 is a prime.

It is not a weakly prime, because it can be changed into another prime (20128737638809) 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, 10064368824404 + 10064368824405.

It is an arithmetic number, because the mean of its divisors is an integer number (10064368824405).

Almost surely, 2^{20128737648809} is an apocalyptic number.

It is an amenable number.

20128737648809 is a deficient number, since it is larger than the sum of its proper divisors (1).

20128737648809 is an equidigital number, since it uses as much as digits as its factorization.

20128737648809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65028096, while the sum is 65.

The spelling of 20128737648809 in words is "twenty trillion, one hundred twenty-eight billion, seven hundred thirty-seven million, six hundred forty-eight thousand, eight hundred nine".