128291 has 2 divisors, whose sum is σ = 128292. Its totient is φ = 128290.

The previous prime is 128287. The next prime is 128311. The reversal of 128291 is 192821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128291 - 2² = 128287 is a prime.

It is not a weakly prime, because it can be changed into another prime (128201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64145 + 64146.

It is an arithmetic number, because the mean of its divisors is an integer number (64146).

2¹²⁸²⁹¹ is an apocalyptic number.

128291 is a deficient number, since it is larger than the sum of its proper divisors (1).

128291 is an equidigital number, since it uses as much as digits as its factorization.

128291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 23.

The square root of 128291 is about 358.1773303826. The cubic root of 128291 is about 50.4350044472.

The spelling of 128291 in words is "one hundred twenty-eight thousand, two hundred ninety-one".