221320 has 32 divisors (see below), whose sum is σ = 544320. Its totient is φ = 80320.

The previous prime is 221317. The next prime is 221327. The reversal of 221320 is 23122.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 221297 and 221306.

It is not an unprimeable number, because it can be changed into a prime (221327) 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, 189 + ... + 691.

It is an arithmetic number, because the mean of its divisors is an integer number (17010).

2²²¹³²⁰ is an apocalyptic number.

221320 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 221320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (272160).

221320 is an abundant number, since it is smaller than the sum of its proper divisors (323000).

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

221320 is a wasteful number, since it uses less digits than its factorization.

221320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525 (or 521 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 221320 is about 470.4465963316. The cubic root of 221320 is about 60.4886029120.

Adding to 221320 its reverse (23122), we get a palindrome (244442).

The spelling of 221320 in words is "two hundred twenty-one thousand, three hundred twenty", and thus it is an iban number.