221920 has 48 divisors (see below), whose sum is σ = 559440. Its totient is φ = 82944.

The previous prime is 221909. The next prime is 221941. The reversal of 221920 is 29122.

It is a happy number.

221920 is digitally balanced in base 3, 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 (16).

It is a junction number, because it is equal to n+sod(n) for n = 221894 and 221903.

It is a congruent number.

It is an unprimeable number.

221920 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 7 ways as a sum of consecutive naturals, for example, 3004 + ... + 3076.

It is an arithmetic number, because the mean of its divisors is an integer number (11655).

2²²¹⁹²⁰ is an apocalyptic number.

221920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279720).

221920 is an abundant number, since it is smaller than the sum of its proper divisors (337520).

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

221920 is a wasteful number, since it uses less digits than its factorization.

221920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 221920 is about 471.0838566540. The cubic root of 221920 is about 60.5432152592.

The spelling of 221920 in words is "two hundred twenty-one thousand, nine hundred twenty".