66520 has 16 divisors (see below), whose sum is σ = 149760. Its totient is φ = 26592.

The previous prime is 66509. The next prime is 66523. The reversal of 66520 is 2566.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66523) 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 in 3 ways as a sum of consecutive naturals, for example, 792 + ... + 871.

It is an arithmetic number, because the mean of its divisors is an integer number (9360).

2⁶⁶⁵²⁰ is an apocalyptic number.

It is an amenable number.

66520 is an abundant number, since it is smaller than the sum of its proper divisors (83240).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74880).

66520 is a wasteful number, since it uses less digits than its factorization.

66520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1674 (or 1670 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 66520 is about 257.9147145860. The cubic root of 66520 is about 40.5182562616.

The spelling of 66520 in words is "sixty-six thousand, five hundred twenty".