128385782809 has 2 divisors, whose sum is σ = 128385782810. Its totient is φ = 128385782808.

The previous prime is 128385782779. The next prime is 128385782813. The reversal of 128385782809 is 908287583821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120788917209 + 7596865600 = 347547^2 + 87160^2 .

It is an emirp because it is prime and its reverse (908287583821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128385782809 - 2¹³ = 128385774617 is a prime.

It is not a weakly prime, because it can be changed into another prime (128385782839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64192891404 + 64192891405.

It is an arithmetic number, because the mean of its divisors is an integer number (64192891405).

Almost surely, 2^128385782809 is an apocalyptic number.

It is an amenable number.

128385782809 is a deficient number, since it is larger than the sum of its proper divisors (1).

128385782809 is an equidigital number, since it uses as much as digits as its factorization.

128385782809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15482880, while the sum is 61.

The spelling of 128385782809 in words is "one hundred twenty-eight billion, three hundred eighty-five million, seven hundred eighty-two thousand, eight hundred nine".