128887 has 4 divisors (see below), whose sum is σ = 140616. Its totient is φ = 117160.

The previous prime is 128879. The next prime is 128903. The reversal of 128887 is 788821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 788821 = 11 ⋅71711.

It is a cyclic number.

It is not a de Polignac number, because 128887 - 2³ = 128879 is a prime.

It is a super-2 number, since 2×128887² = 33223717538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5848 + ... + 5869.

It is an arithmetic number, because the mean of its divisors is an integer number (35154).

2¹²⁸⁸⁸⁷ is an apocalyptic number.

128887 is a deficient number, since it is larger than the sum of its proper divisors (11729).

128887 is a wasteful number, since it uses less digits than its factorization.

128887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11728.

The product of its digits is 7168, while the sum is 34.

The square root of 128887 is about 359.0083564487. The cubic root of 128887 is about 50.5129855833.

The spelling of 128887 in words is "one hundred twenty-eight thousand, eight hundred eighty-seven".