128566 has 4 divisors (see below), whose sum is σ = 192852. Its totient is φ = 64282.

The previous prime is 128563. The next prime is 128591. The reversal of 128566 is 665821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 665821 = 13 ⋅51217.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32140 + ... + 32143.

It is an arithmetic number, because the mean of its divisors is an integer number (48213).

2¹²⁸⁵⁶⁶ is an apocalyptic number.

128566 is a deficient number, since it is larger than the sum of its proper divisors (64286).

128566 is an equidigital number, since it uses as much as digits as its factorization.

128566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64285.

The product of its digits is 2880, while the sum is 28.

The square root of 128566 is about 358.5610129392. The cubic root of 128566 is about 50.4710156194.

The spelling of 128566 in words is "one hundred twenty-eight thousand, five hundred sixty-six".