128771 has 4 divisors (see below), whose sum is σ = 130944. Its totient is φ = 126600.

The previous prime is 128767. The next prime is 128813. The reversal of 128771 is 177821.

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

It is a cyclic number.

It is not a de Polignac number, because 128771 - 2² = 128767 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 128771.

It is not an unprimeable number, because it can be changed into a prime (128761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 995 + ... + 1116.

It is an arithmetic number, because the mean of its divisors is an integer number (32736).

2¹²⁸⁷⁷¹ is an apocalyptic number.

128771 is a deficient number, since it is larger than the sum of its proper divisors (2173).

128771 is an equidigital number, since it uses as much as digits as its factorization.

128771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2172.

The product of its digits is 784, while the sum is 26.

The square root of 128771 is about 358.8467639536. The cubic root of 128771 is about 50.4978269169.

The spelling of 128771 in words is "one hundred twenty-eight thousand, seven hundred seventy-one".