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8128 = 26127

8128 has 14 divisors (see below), whose sum is σ = 16256. Its totient is φ = 4032.

The previous prime is 8123. The next prime is 8147. The reversal of 8128 is 8218.

It is a happy number.

8128 is a nontrivial binomial coefficient, being equal to C(128, 2).

It is a harmonic number, since the harmonic mean of its divisors is an integer.

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

It is a nialpdrome in base 2.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1 + ... + 127.

28128 is an apocalyptic number.

8128 is the 127-th triangular number and also the 64-th hexagonal number.

8128 is the 43-rd centered nonagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8128).

8128 is a perfect number, since it is equal to the sum of its proper divisors.

8128 is a wasteful number, since it uses less digits than its factorization.

8128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139 (or 129 counting only the distinct ones).

The product of its digits is 128, while the sum is 19.

The square root of 8128 is about 90.1554213567. The cubic root of 8128 is about 20.1061027813.

Adding to 8128 its product of digits (128), we get a triangular number (8256 = T128).

Subtracting from 8128 its product of digits (128), we obtain a cube (8000 = 203).

It can be divided in two parts, 812 and 8, that added together give a triangular number (820 = T40).

The spelling of 8128 in words is "eight thousand, one hundred twenty-eight".

Divisors: 1 2 4 8 16 32 64 127 254 508 1016 2032 4064 8128