20858317 has 2 divisors, whose sum is σ = 20858318. Its totient is φ = 20858316.

The previous prime is 20858297. The next prime is 20858323. The reversal of 20858317 is 71385802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13920361 + 6937956 = 3731^2 + 2634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20858317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20858347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10429158 + 10429159.

It is an arithmetic number, because the mean of its divisors is an integer number (10429159).

Almost surely, 2^20858317 is an apocalyptic number.

It is an amenable number.

20858317 is a deficient number, since it is larger than the sum of its proper divisors (1).

20858317 is an equidigital number, since it uses as much as digits as its factorization.

20858317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 20858317 is about 4567.0906494179. The cubic root of 20858317 is about 275.2705524686.

The spelling of 20858317 in words is "twenty million, eight hundred fifty-eight thousand, three hundred seventeen".