20305321 has 2 divisors, whose sum is σ = 20305322. Its totient is φ = 20305320.

The previous prime is 20305277. The next prime is 20305333. The reversal of 20305321 is 12350302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20115225 + 190096 = 4485^2 + 436^2 .

It is a cyclic number.

It is not a de Polignac number, because 20305321 - 2¹⁷ = 20174249 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20305295 and 20305304.

It is not a weakly prime, because it can be changed into another prime (20305391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10152660 + 10152661.

It is an arithmetic number, because the mean of its divisors is an integer number (10152661).

Almost surely, 2^20305321 is an apocalyptic number.

It is an amenable number.

20305321 is a deficient number, since it is larger than the sum of its proper divisors (1).

20305321 is an equidigital number, since it uses as much as digits as its factorization.

20305321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 20305321 is about 4506.1425854049. The cubic root of 20305321 is about 272.8160729387.

Adding to 20305321 its reverse (12350302), we get a palindrome (32655623).

The spelling of 20305321 in words is "twenty million, three hundred five thousand, three hundred twenty-one".