128971 has 2 divisors, whose sum is σ = 128972. Its totient is φ = 128970.

The previous prime is 128969. The next prime is 128981. The reversal of 128971 is 179821.

It is a weak prime.

It is an emirp because it is prime and its reverse (179821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128971 - 2¹ = 128969 is a prime.

Together with 128969, it forms a pair of twin primes.

It is an Ulam number.

128971 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (128941) 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 as a sum of consecutive naturals, namely, 64485 + 64486.

It is an arithmetic number, because the mean of its divisors is an integer number (64486).

2¹²⁸⁹⁷¹ is an apocalyptic number.

128971 is a deficient number, since it is larger than the sum of its proper divisors (1).

128971 is an equidigital number, since it uses as much as digits as its factorization.

128971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 28.

The square root of 128971 is about 359.1253263138. The cubic root of 128971 is about 50.5239568716.

It can be divided in two parts, 1289 and 71, that multiplied together give a palindrome (91519).

The spelling of 128971 in words is "one hundred twenty-eight thousand, nine hundred seventy-one".