128647 has 4 divisors (see below), whose sum is σ = 130000. Its totient is φ = 127296.

The previous prime is 128629. The next prime is 128657. The reversal of 128647 is 746821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 746821 = 31 ⋅24091.

It is a cyclic number.

It is not a de Polignac number, because 128647 - 2⁷ = 128519 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128657) 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 in 3 ways as a sum of consecutive naturals, for example, 522 + ... + 727.

It is an arithmetic number, because the mean of its divisors is an integer number (32500).

2¹²⁸⁶⁴⁷ is an apocalyptic number.

128647 is a deficient number, since it is larger than the sum of its proper divisors (1353).

128647 is a wasteful number, since it uses less digits than its factorization.

128647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1352.

The product of its digits is 2688, while the sum is 28.

The square root of 128647 is about 358.6739466424. The cubic root of 128647 is about 50.4816127550.

The spelling of 128647 in words is "one hundred twenty-eight thousand, six hundred forty-seven".