20105321 has 2 divisors, whose sum is σ = 20105322. Its totient is φ = 20105320.

The previous prime is 20105317. The next prime is 20105333. The reversal of 20105321 is 12350102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15960025 + 4145296 = 3995^2 + 2036^2 .

It is a cyclic number.

It is not a de Polignac number, because 20105321 - 2² = 20105317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20105296 and 20105305.

It is not a weakly prime, because it can be changed into another prime (20105341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10052660 + 10052661.

It is an arithmetic number, because the mean of its divisors is an integer number (10052661).

Almost surely, 2^20105321 is an apocalyptic number.

It is an amenable number.

20105321 is a deficient number, since it is larger than the sum of its proper divisors (1).

20105321 is an equidigital number, since it uses as much as digits as its factorization.

20105321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 20105321 is about 4483.8957391982. The cubic root of 20105321 is about 271.9174030133.

Adding to 20105321 its reverse (12350102), we get a palindrome (32455423).

The spelling of 20105321 in words is "twenty million, one hundred five thousand, three hundred twenty-one".