20912317 has 2 divisors, whose sum is σ = 20912318. Its totient is φ = 20912316.

The previous prime is 20912303. The next prime is 20912341. The reversal of 20912317 is 71321902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11737476 + 9174841 = 3426^2 + 3029^2 .

It is a cyclic number.

It is not a de Polignac number, because 20912317 - 2⁷ = 20912189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20912291 and 20912300.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20912377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10456158 + 10456159.

It is an arithmetic number, because the mean of its divisors is an integer number (10456159).

Almost surely, 2^20912317 is an apocalyptic number.

It is an amenable number.

20912317 is a deficient number, since it is larger than the sum of its proper divisors (1).

20912317 is an equidigital number, since it uses as much as digits as its factorization.

20912317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 20912317 is about 4572.9986879508. The cubic root of 20912317 is about 275.5078966515.

The spelling of 20912317 in words is "twenty million, nine hundred twelve thousand, three hundred seventeen".