128261 has 8 divisors (see below), whose sum is σ = 149184. Its totient is φ = 108000.

The previous prime is 128257. The next prime is 128273. The reversal of 128261 is 162821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128261 - 2² = 128257 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 386 + ... + 636.

It is an arithmetic number, because the mean of its divisors is an integer number (18648).

2¹²⁸²⁶¹ is an apocalyptic number.

It is an amenable number.

128261 is a deficient number, since it is larger than the sum of its proper divisors (20923).

128261 is an equidigital number, since it uses as much as digits as its factorization.

128261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331.

The product of its digits is 192, while the sum is 20.

The square root of 128261 is about 358.1354492367. The cubic root of 128261 is about 50.4310728436.

The spelling of 128261 in words is "one hundred twenty-eight thousand, two hundred sixty-one".