305221 has 6 divisors (see below), whose sum is σ = 355110. Its totient is φ = 261576.

The previous prime is 305219. The next prime is 305231. The reversal of 305221 is 122503.

It can be written as a sum of positive squares in only one way, i.e., 261121 + 44100 = 511^2 + 210^2 .

It is not a de Polignac number, because 305221 - 2¹ = 305219 is a prime.

305221 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (305231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3066 + ... + 3163.

It is an arithmetic number, because the mean of its divisors is an integer number (59185).

2³⁰⁵²²¹ is an apocalyptic number.

It is an amenable number.

305221 is a deficient number, since it is larger than the sum of its proper divisors (49889).

305221 is an equidigital number, since it uses as much as digits as its factorization.

305221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6243 (or 6236 counting only the distinct ones).

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

The square root of 305221 is about 552.4680986265. The cubic root of 305221 is about 67.3294091974.

Adding to 305221 its reverse (122503), we get a palindrome (427724).

The spelling of 305221 in words is "three hundred five thousand, two hundred twenty-one".