220806 has 40 divisors (see below), whose sum is σ = 522720. Its totient is φ = 69552.

The previous prime is 220793. The next prime is 220807. The reversal of 220806 is 608022.

Added to its reverse (608022) it gives a triangular number (828828 = T₁₂₈₇).

220806 is an esthetic number in base 15, because in such base its adjacent digits differ by 1.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220807) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4675 + ... + 4721.

It is an arithmetic number, because the mean of its divisors is an integer number (13068).

2²²⁰⁸⁰⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 220806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261360).

220806 is an abundant number, since it is smaller than the sum of its proper divisors (301914).

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

220806 is a wasteful number, since it uses less digits than its factorization.

220806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 220806 is about 469.8999893594. The cubic root of 220806 is about 60.4417397847.

Adding to 220806 its reverse (608022), we get a palindrome (828828).

The spelling of 220806 in words is "two hundred twenty thousand, eight hundred six".