66560 has 44 divisors (see below), whose sum is σ = 171948. Its totient is φ = 24576.

The previous prime is 66553. The next prime is 66569. The reversal of 66560 is 6566.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16384 + 50176 = 128^2 + 224^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66569) by changing a digit.

66560 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (2) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5114 + ... + 5126.

2⁶⁶⁵⁶⁰ 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 66560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85974).

66560 is an abundant number, since it is smaller than the sum of its proper divisors (105388).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66560 is a wasteful number, since it uses less digits than its factorization.

66560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 66560 is about 257.9922479456. The cubic root of 66560 is about 40.5263761528.

It can be divided in two parts, 66 and 560, that added together give a palindrome (626).

The spelling of 66560 in words is "sixty-six thousand, five hundred sixty".