20730173 has 2 divisors, whose sum is σ = 20730174. Its totient is φ = 20730172.

The previous prime is 20730167. The next prime is 20730187. The reversal of 20730173 is 37103702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19377604 + 1352569 = 4402^2 + 1163^2 .

It is a cyclic number.

It is not a de Polignac number, because 20730173 - 2⁶ = 20730109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20730373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10365086 + 10365087.

It is an arithmetic number, because the mean of its divisors is an integer number (10365087).

Almost surely, 2^20730173 is an apocalyptic number.

It is an amenable number.

20730173 is a deficient number, since it is larger than the sum of its proper divisors (1).

20730173 is an equidigital number, since it uses as much as digits as its factorization.

20730173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 882, while the sum is 23.

The square root of 20730173 is about 4553.0399734683. The cubic root of 20730173 is about 274.7056818132.

Adding to 20730173 its reverse (37103702), we get a palindrome (57833875).

The spelling of 20730173 in words is "twenty million, seven hundred thirty thousand, one hundred seventy-three".