20967209 has 2 divisors, whose sum is σ = 20967210. Its totient is φ = 20967208.

The previous prime is 20967161. The next prime is 20967227. The reversal of 20967209 is 90276902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 896809 = 4480^2 + 947^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20967209 is a prime.

It is a Chen prime.

It is equal to p_1327994 and since 20967209 and 1327994 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20967259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10483604 + 10483605.

It is an arithmetic number, because the mean of its divisors is an integer number (10483605).

Almost surely, 2^20967209 is an apocalyptic number.

It is an amenable number.

20967209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20967209 is an equidigital number, since it uses as much as digits as its factorization.

20967209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 20967209 is about 4578.9965057860. The cubic root of 20967209 is about 275.7487430169.

The spelling of 20967209 in words is "twenty million, nine hundred sixty-seven thousand, two hundred nine".