220864 has 56 divisors (see below), whose sum is σ = 548640. Its totient is φ = 86016.

The previous prime is 220861. The next prime is 220873. The reversal of 220864 is 468022.

220864 = T₄₉ + T₅₀ + ... + T₁₁₂.

220864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (56).

It is not an unprimeable number, because it can be changed into a prime (220861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7602 + ... + 7630.

2²²⁰⁸⁶⁴ 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 220864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274320).

220864 is an abundant number, since it is smaller than the sum of its proper divisors (327776).

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

220864 is a wasteful number, since it uses less digits than its factorization.

220864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 55 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 220864 is about 469.9617005672. The cubic root of 220864 is about 60.4470314797.

Adding to 220864 its reverse (468022), we get a palindrome (688886).

The spelling of 220864 in words is "two hundred twenty thousand, eight hundred sixty-four".