20111212085717 has 2 divisors, whose sum is σ = 20111212085718. Its totient is φ = 20111212085716.

The previous prime is 20111212085681. The next prime is 20111212085747. The reversal of 20111212085717 is 71758021211102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17746386321316 + 2364825764401 = 4212646^2 + 1537799^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111212085717 - 2¹⁰ = 20111212084693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20111212085747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055606042858 + 10055606042859.

It is an arithmetic number, because the mean of its divisors is an integer number (10055606042859).

Almost surely, 2^{20111212085717} is an apocalyptic number.

It is an amenable number.

20111212085717 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111212085717 is an equidigital number, since it uses as much as digits as its factorization.

20111212085717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15680, while the sum is 38.

Adding to 20111212085717 its reverse (71758021211102), we get a palindrome (91869233296819).

The spelling of 20111212085717 in words is "twenty trillion, one hundred eleven billion, two hundred twelve million, eighty-five thousand, seven hundred seventeen".