221305 has 8 divisors (see below), whose sum is σ = 303552. Its totient is φ = 151728.

The previous prime is 221303. The next prime is 221311. The reversal of 221305 is 503122.

221305 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221305 - 2¹ = 221303 is a prime.

It is a Duffinian number.

221305 is a lucky number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (221303) 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, 3127 + ... + 3196.

It is an arithmetic number, because the mean of its divisors is an integer number (37944).

2²²¹³⁰⁵ is an apocalyptic number.

It is an amenable number.

221305 is a deficient number, since it is larger than the sum of its proper divisors (82247).

221305 is an equidigital number, since it uses as much as digits as its factorization.

221305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6335.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 221305 is about 470.4306537631. The cubic root of 221305 is about 60.4872363394.

Adding to 221305 its reverse (503122), we get a palindrome (724427).

The spelling of 221305 in words is "two hundred twenty-one thousand, three hundred five".