Adding to 6540 its sum of digits (15), we get a triangular number (6555 = T114).
Adding to 6540 its reverse (456), we get a palindrome (6996).
Subtracting from 6540 its reverse (456), we obtain a square (6084 = 782).
6540 is nontrivially palindromic in base 14.
It is a nialpdrome in base 9 and base 10.
It is a zygodrome in base 2 and base 9.
It is a congruent number.
26540 is an apocalyptic number.
6540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 6540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9240).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
6540 is a wasteful number, since it uses less digits than its factorization.
6540 is an evil number, because the sum of its binary digits is even.
The square root of 6540 is about 80.8702664766. The cubic root of 6540 is about 18.7007596897.
The spelling of 6540 in words is "six thousand, five hundred forty".