128387 has 4 divisors (see below), whose sum is σ = 146736. Its totient is φ = 110040.

The previous prime is 128377. The next prime is 128389. The reversal of 128387 is 783821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 783821 = 139 ⋅5639.

It is not a de Polignac number, because 128387 - 2¹⁰ = 127363 is a prime.

It is a d-powerful number, because it can be written as 1 + 2⁴ + 3⁸ + 8² + 8⁴ + 7⁶ .

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 128387.

It is not an unprimeable number, because it can be changed into a prime (128389) 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, 9164 + ... + 9177.

It is an arithmetic number, because the mean of its divisors is an integer number (36684).

2¹²⁸³⁸⁷ is an apocalyptic number.

128387 is a deficient number, since it is larger than the sum of its proper divisors (18349).

128387 is an equidigital number, since it uses as much as digits as its factorization.

128387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18348.

The product of its digits is 2688, while the sum is 29.

The square root of 128387 is about 358.3113171531. The cubic root of 128387 is about 50.4475814616.

It can be divided in two parts, 128 and 387, that added together give a palindrome (515).

The spelling of 128387 in words is "one hundred twenty-eight thousand, three hundred eighty-seven".