128671 has 4 divisors (see below), whose sum is σ = 129472. Its totient is φ = 127872.

The previous prime is 128669. The next prime is 128677. The reversal of 128671 is 176821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 176821 = 151 ⋅1171.

It is a cyclic number.

It is not a de Polignac number, because 128671 - 2¹ = 128669 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128677) 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 in 3 ways as a sum of consecutive naturals, for example, 66 + ... + 511.

It is an arithmetic number, because the mean of its divisors is an integer number (32368).

2¹²⁸⁶⁷¹ is an apocalyptic number.

128671 is a deficient number, since it is larger than the sum of its proper divisors (801).

128671 is an equidigital number, since it uses as much as digits as its factorization.

128671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800.

The product of its digits is 672, while the sum is 25.

The square root of 128671 is about 358.7074016521. The cubic root of 128671 is about 50.4847517928.

The spelling of 128671 in words is "one hundred twenty-eight thousand, six hundred seventy-one".