128121 has 8 divisors (see below), whose sum is σ = 195264. Its totient is φ = 73200.

The previous prime is 128119. The next prime is 128147. The reversal of 128121 is 121821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128121 - 2¹ = 128119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128121.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 128121.

It is not an unprimeable number, because it can be changed into a prime (128111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3030 + ... + 3071.

It is an arithmetic number, because the mean of its divisors is an integer number (24408).

2¹²⁸¹²¹ is an apocalyptic number.

It is an amenable number.

128121 is a deficient number, since it is larger than the sum of its proper divisors (67143).

128121 is an equidigital number, since it uses as much as digits as its factorization.

128121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6111.

The product of its digits is 32, while the sum is 15.

The square root of 128121 is about 357.9399390959. The cubic root of 128121 is about 50.4127172494.

Adding to 128121 its reverse (121821), we get a palindrome (249942).

The spelling of 128121 in words is "one hundred twenty-eight thousand, one hundred twenty-one".