66220 has 48 divisors (see below), whose sum is σ = 177408. Its totient is φ = 20160.

The previous prime is 66191. The next prime is 66221. The reversal of 66220 is 2266.

66220 = T₉₉ + T₁₀₀ + ... + T₁₁₀.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 66194 and 66203.

It is not an unprimeable number, because it can be changed into a prime (66221) by changing a digit.

66220 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1519 + ... + 1561.

It is an arithmetic number, because the mean of its divisors is an integer number (3696).

2⁶⁶²²⁰ 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 66220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88704).

66220 is an abundant number, since it is smaller than the sum of its proper divisors (111188).

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

66220 is a wasteful number, since it uses less digits than its factorization.

66220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 66220 is about 257.3324697740. The cubic root of 66220 is about 40.4572530735.

Adding to 66220 its reverse (2266), we get a palindrome (68486).

It can be divided in two parts, 6 and 6220, that added together give a palindrome (6226).

The spelling of 66220 in words is "sixty-six thousand, two hundred twenty".