128167609 has 12 divisors (see below), whose sum is σ = 133304292. Its totient is φ = 123221280.

The previous prime is 128167603. The next prime is 128167639. The reversal of 128167609 is 906761821.

It can be written as a sum of positive squares in 2 ways, for example, as 126630009 + 1537600 = 11253^2 + 1240^2 .

It is not a de Polignac number, because 128167609 - 2³ = 128167601 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128167601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 188979 + ... + 189655.

It is an arithmetic number, because the mean of its divisors is an integer number (11108691).

Almost surely, 2^128167609 is an apocalyptic number.

It is an amenable number.

128167609 is a deficient number, since it is larger than the sum of its proper divisors (5136683).

128167609 is an equidigital number, since it uses as much as digits as its factorization.

128167609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936 (or 905 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 128167609 is about 11321.1134169745. The cubic root of 128167609 is about 504.1882970419.

The spelling of 128167609 in words is "one hundred twenty-eight million, one hundred sixty-seven thousand, six hundred nine".