1221001205717 has 2 divisors, whose sum is σ = 1221001205718. Its totient is φ = 1221001205716.

The previous prime is 1221001205701. The next prime is 1221001205761. The reversal of 1221001205717 is 7175021001221.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 938701325956 + 282299879761 = 968866^2 + 531319^2 .

It is an emirp because it is prime and its reverse (7175021001221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221001205717 - 2⁴ = 1221001205701 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221001205717.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221001205317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610500602858 + 610500602859.

It is an arithmetic number, because the mean of its divisors is an integer number (610500602859).

Almost surely, 2^{1221001205717} is an apocalyptic number.

It is an amenable number.

1221001205717 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221001205717 is an equidigital number, since it uses as much as digits as its factorization.

1221001205717 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1960, while the sum is 29.

Adding to 1221001205717 its reverse (7175021001221), we get a palindrome (8396022206938).

The spelling of 1221001205717 in words is "one trillion, two hundred twenty-one billion, one million, two hundred five thousand, seven hundred seventeen".