128158817 has 2 divisors, whose sum is σ = 128158818. Its totient is φ = 128158816.

The previous prime is 128158813. The next prime is 128158871. The reversal of 128158817 is 718851821.

Together with next prime (128158871) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67256401 + 60902416 = 8201^2 + 7804^2 .

It is a cyclic number.

It is not a de Polignac number, because 128158817 - 2² = 128158813 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128158813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64079408 + 64079409.

It is an arithmetic number, because the mean of its divisors is an integer number (64079409).

Almost surely, 2^128158817 is an apocalyptic number.

It is an amenable number.

128158817 is a deficient number, since it is larger than the sum of its proper divisors (1).

128158817 is an equidigital number, since it uses as much as digits as its factorization.

128158817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35840, while the sum is 41.

The square root of 128158817 is about 11320.7251092852. The cubic root of 128158817 is about 504.1767680633.

The spelling of 128158817 in words is "one hundred twenty-eight million, one hundred fifty-eight thousand, eight hundred seventeen".