20304321221 has 4 divisors (see below), whose sum is σ = 20308297452. Its totient is φ = 20300344992.

The previous prime is 20304321217. The next prime is 20304321269. The reversal of 20304321221 is 12212340302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 596092225 + 19708228996 = 24415^2 + 140386^2 .

It is a cyclic number.

It is not a de Polignac number, because 20304321221 - 2² = 20304321217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20304321193 and 20304321202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20304320221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1980446 + ... + 1990671.

It is an arithmetic number, because the mean of its divisors is an integer number (5077074363).

Almost surely, 2^20304321221 is an apocalyptic number.

It is an amenable number.

20304321221 is a deficient number, since it is larger than the sum of its proper divisors (3976231).

20304321221 is an equidigital number, since it uses as much as digits as its factorization.

20304321221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3976230.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 20304321221 its reverse (12212340302), we get a palindrome (32516661523).

The spelling of 20304321221 in words is "twenty billion, three hundred four million, three hundred twenty-one thousand, two hundred twenty-one".