128549 has 2 divisors, whose sum is σ = 128550. Its totient is φ = 128548.

The previous prime is 128521. The next prime is 128551. The reversal of 128549 is 945821.

128549 = 206² + 207² + 208².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66049 + 62500 = 257^2 + 250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128549 is a prime.

It is a Sophie Germain prime.

Together with 128551, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64274 + 64275.

It is an arithmetic number, because the mean of its divisors is an integer number (64275).

2¹²⁸⁵⁴⁹ is an apocalyptic number.

It is an amenable number.

128549 is a deficient number, since it is larger than the sum of its proper divisors (1).

128549 is an equidigital number, since it uses as much as digits as its factorization.

128549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 29.

The square root of 128549 is about 358.5373062876. The cubic root of 128549 is about 50.4687909641.

The spelling of 128549 in words is "one hundred twenty-eight thousand, five hundred forty-nine".