21220044712717 has 2 divisors, whose sum is σ = 21220044712718. Its totient is φ = 21220044712716.

The previous prime is 21220044712693. The next prime is 21220044712729. The reversal of 21220044712717 is 71721744002212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21216977103721 + 3067608996 = 4606189^2 + 55386^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220044712717 - 2⁷ = 21220044712589 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21220044712717.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220044712747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610022356358 + 10610022356359.

It is an arithmetic number, because the mean of its divisors is an integer number (10610022356359).

Almost surely, 2^{21220044712717} is an apocalyptic number.

It is an amenable number.

21220044712717 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220044712717 is an equidigital number, since it uses as much as digits as its factorization.

21220044712717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87808, while the sum is 40.

Adding to 21220044712717 its reverse (71721744002212), we get a palindrome (92941788714929).

The spelling of 21220044712717 in words is "twenty-one trillion, two hundred twenty billion, forty-four million, seven hundred twelve thousand, seven hundred seventeen".