20321573 has 2 divisors, whose sum is σ = 20321574. Its totient is φ = 20321572.

The previous prime is 20321557. The next prime is 20321599. The reversal of 20321573 is 37512302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18992164 + 1329409 = 4358^2 + 1153^2 .

It is a cyclic number.

It is not a de Polignac number, because 20321573 - 2⁴ = 20321557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20321173) 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, 10160786 + 10160787.

It is an arithmetic number, because the mean of its divisors is an integer number (10160787).

Almost surely, 2^20321573 is an apocalyptic number.

It is an amenable number.

20321573 is a deficient number, since it is larger than the sum of its proper divisors (1).

20321573 is an equidigital number, since it uses as much as digits as its factorization.

20321573 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 20321573 is about 4507.9455409310. The cubic root of 20321573 is about 272.8888391597. Note that the first 4 decimals are identical.

Adding to 20321573 its reverse (37512302), we get a palindrome (57833875).

The spelling of 20321573 in words is "twenty million, three hundred twenty-one thousand, five hundred seventy-three".