7128 has 40 divisors (see below), whose sum is σ = 21780.
Its totient is φ = 2160.
The previous prime is 7127. The next prime is 7129. The reversal of 7128 is 8217.
It is an interprime number because it is at equal distance from previous prime (7127) and next prime (7129).
It is a Harshad number since it is a multiple of its sum of digits (18).
Its product of digits (112) is a multiple of the sum of its prime divisors (16).
It is a nialpdrome in base 6.
It is a self number, because there is not a number n which added to its sum of digits gives 7128.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (7121) by changing a digit.
It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 643 + ... + 653.
27128 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 7128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10890).
7128 is an abundant number, since it is smaller than the sum of its proper divisors (14652).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
7128 is a wasteful number, since it uses less digits than its factorization.
7128 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 29 (or 16 counting only the distinct ones).
The product of its digits is 112, while the sum is 18.
The square root of 7128 is about 84.4274836768.
The cubic root of 7128 is about 19.2452059800.
Subtracting 7128 from its reverse (8217), we obtain a square (1089 = 332).
It can be divided in two parts, 71 and 28, that added together give a palindrome (99).
The spelling of 7128 in words is "seven thousand, one hundred twenty-eight".