20859173 has 2 divisors, whose sum is σ = 20859174. Its totient is φ = 20859172.

The previous prime is 20859143. The next prime is 20859199. The reversal of 20859173 is 37195802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15108769 + 5750404 = 3887^2 + 2398^2 .

It is a cyclic number.

It is not a de Polignac number, because 20859173 - 2¹⁶ = 20793637 is a prime.

It is a super-3 number, since 3×20859173³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20859103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10429586 + 10429587.

It is an arithmetic number, because the mean of its divisors is an integer number (10429587).

Almost surely, 2^20859173 is an apocalyptic number.

It is an amenable number.

20859173 is a deficient number, since it is larger than the sum of its proper divisors (1).

20859173 is an equidigital number, since it uses as much as digits as its factorization.

20859173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 20859173 is about 4567.1843623835. The cubic root of 20859173 is about 275.2743180068.

The spelling of 20859173 in words is "twenty million, eight hundred fifty-nine thousand, one hundred seventy-three".