220656 has 20 divisors (see below), whose sum is σ = 570152. Its totient is φ = 73536.

The previous prime is 220613. The next prime is 220663. The reversal of 220656 is 656022.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

220656 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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2251 + ... + 2346.

2²²⁰⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

220656 is an abundant number, since it is smaller than the sum of its proper divisors (349496).

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

220656 is a wasteful number, since it uses less digits than its factorization.

220656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4608 (or 4602 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 220656 is about 469.7403538126. The cubic root of 220656 is about 60.4280500680.

Adding to 220656 its reverse (656022), we get a palindrome (876678).

The spelling of 220656 in words is "two hundred twenty thousand, six hundred fifty-six".