220428 has 48 divisors (see below), whose sum is σ = 619360. Its totient is φ = 67392.

The previous prime is 220421. The next prime is 220447. The reversal of 220428 is 824022.

220428 = T₁₁₇ + T₁₁₈ + ... + T₁₄₂.

220428 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a self number, because there is not a number n which added to its sum of digits gives 220428.

It is not an unprimeable number, because it can be changed into a prime (220421) by changing a digit.

220428 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, 1326 + ... + 1482.

2²²⁰⁴²⁸ 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 220428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309680).

220428 is an abundant number, since it is smaller than the sum of its proper divisors (398932).

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

220428 is a wasteful number, since it uses less digits than its factorization.

220428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 220428 is about 469.4976038278. The cubic root of 220428 is about 60.4072298116.

220428 divided by its sum of digits (18) gives a triangular number (12246 = T₁₅₆).

The spelling of 220428 in words is "two hundred twenty thousand, four hundred twenty-eight".