128115989857 has 2 divisors, whose sum is σ = 128115989858. Its totient is φ = 128115989856.

The previous prime is 128115989843. The next prime is 128115989887. The reversal of 128115989857 is 758989511821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121106784016 + 7009205841 = 348004^2 + 83721^2 .

It is a cyclic number.

It is not a de Polignac number, because 128115989857 - 2²³ = 128107601249 is a prime.

It is not a weakly prime, because it can be changed into another prime (128115989887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64057994928 + 64057994929.

It is an arithmetic number, because the mean of its divisors is an integer number (64057994929).

Almost surely, 2^128115989857 is an apocalyptic number.

It is an amenable number.

128115989857 is a deficient number, since it is larger than the sum of its proper divisors (1).

128115989857 is an equidigital number, since it uses as much as digits as its factorization.

128115989857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14515200, while the sum is 64.

The spelling of 128115989857 in words is "one hundred twenty-eight billion, one hundred fifteen million, nine hundred eighty-nine thousand, eight hundred fifty-seven".