20641717 has 2 divisors, whose sum is σ = 20641718. Its totient is φ = 20641716.

The previous prime is 20641679. The next prime is 20641721. The reversal of 20641717 is 71714602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10491121 + 10150596 = 3239^2 + 3186^2 .

It is a cyclic number.

It is not a de Polignac number, because 20641717 - 2⁷ = 20641589 is a prime.

It is equal to p_1308682 and since 20641717 and 1308682 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20641727) 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, 10320858 + 10320859.

It is an arithmetic number, because the mean of its divisors is an integer number (10320859).

Almost surely, 2^20641717 is an apocalyptic number.

It is an amenable number.

20641717 is a deficient number, since it is larger than the sum of its proper divisors (1).

20641717 is an equidigital number, since it uses as much as digits as its factorization.

20641717 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 20641717 is about 4543.3156394862. The cubic root of 20641717 is about 274.3144001470.

The spelling of 20641717 in words is "twenty million, six hundred forty-one thousand, seven hundred seventeen".