304311221 has 6 divisors (see below), whose sum is σ = 314445366. Its totient is φ = 294493800.

The previous prime is 304311209. The next prime is 304311223. The reversal of 304311221 is 122113403.

It can be written as a sum of positive squares in only one way, i.e., 290702500 + 13608721 = 17050^2 + 3689^2 .

It is not a de Polignac number, because 304311221 - 2⁶ = 304311157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 304311221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (304311223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 157370 + ... + 159291.

It is an arithmetic number, because the mean of its divisors is an integer number (52407561).

Almost surely, 2^304311221 is an apocalyptic number.

304311221 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

304311221 is a deficient number, since it is larger than the sum of its proper divisors (10134145).

304311221 is an equidigital number, since it uses as much as digits as its factorization.

304311221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316723 (or 316692 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 304311221 is about 17444.5183653777. The cubic root of 304311221 is about 672.6244586611.

Adding to 304311221 its reverse (122113403), we get a palindrome (426424624).

The spelling of 304311221 in words is "three hundred four million, three hundred eleven thousand, two hundred twenty-one".