20516173 has 2 divisors, whose sum is σ = 20516174. Its totient is φ = 20516172.

The previous prime is 20516149. The next prime is 20516183. The reversal of 20516173 is 37161502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12659364 + 7856809 = 3558^2 + 2803^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20516173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20516123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258086 + 10258087.

It is an arithmetic number, because the mean of its divisors is an integer number (10258087).

Almost surely, 2^20516173 is an apocalyptic number.

It is an amenable number.

20516173 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516173 is an equidigital number, since it uses as much as digits as its factorization.

20516173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 20516173 is about 4529.4782260212. The cubic root of 20516173 is about 273.7571373493.

Adding to 20516173 its reverse (37161502), we get a palindrome (57677675).

The spelling of 20516173 in words is "twenty million, five hundred sixteen thousand, one hundred seventy-three".