20916317 has 2 divisors, whose sum is σ = 20916318. Its totient is φ = 20916316.

The previous prime is 20916299. The next prime is 20916331. The reversal of 20916317 is 71361902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18541636 + 2374681 = 4306^2 + 1541^2 .

It is a cyclic number.

It is not a de Polignac number, because 20916317 - 2¹⁴ = 20899933 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20916317.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20912317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10458158 + 10458159.

It is an arithmetic number, because the mean of its divisors is an integer number (10458159).

Almost surely, 2^20916317 is an apocalyptic number.

It is an amenable number.

20916317 is a deficient number, since it is larger than the sum of its proper divisors (1).

20916317 is an equidigital number, since it uses as much as digits as its factorization.

20916317 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 29.

The square root of 20916317 is about 4573.4360168259. The cubic root of 20916317 is about 275.5254614408.

The spelling of 20916317 in words is "twenty million, nine hundred sixteen thousand, three hundred seventeen".