20906317 has 2 divisors, whose sum is σ = 20906318. Its totient is φ = 20906316.

The previous prime is 20906297. The next prime is 20906329. The reversal of 20906317 is 71360902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14280841 + 6625476 = 3779^2 + 2574^2 .

It is a cyclic number.

It is not a de Polignac number, because 20906317 - 2¹⁹ = 20382029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20906377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10453158 + 10453159.

It is an arithmetic number, because the mean of its divisors is an integer number (10453159).

Almost surely, 2^20906317 is an apocalyptic number.

It is an amenable number.

20906317 is a deficient number, since it is larger than the sum of its proper divisors (1).

20906317 is an equidigital number, since it uses as much as digits as its factorization.

20906317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 20906317 is about 4572.3426162089. The cubic root of 20906317 is about 275.4815452673.

The spelling of 20906317 in words is "twenty million, nine hundred six thousand, three hundred seventeen".