128105 has 4 divisors (see below), whose sum is σ = 153732. Its totient is φ = 102480.

The previous prime is 128099. The next prime is 128111. The reversal of 128105 is 501821.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (128099) and next prime (128111).

It can be written as a sum of positive squares in 2 ways, for example, as 33856 + 94249 = 184^2 + 307^2 .

It is not a de Polignac number, because 128105 - 2⁸ = 127849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 128105.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12806 + ... + 12815.

It is an arithmetic number, because the mean of its divisors is an integer number (38433).

2¹²⁸¹⁰⁵ is an apocalyptic number.

It is an amenable number.

128105 is a deficient number, since it is larger than the sum of its proper divisors (25627).

128105 is an equidigital number, since it uses as much as digits as its factorization.

128105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25626.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 128105 is about 357.9175882798. The cubic root of 128105 is about 50.4106186159.

Adding to 128105 its reverse (501821), we get a palindrome (629926).

The spelling of 128105 in words is "one hundred twenty-eight thousand, one hundred five".