1211222010221 has 2 divisors, whose sum is σ = 1211222010222. Its totient is φ = 1211222010220.

The previous prime is 1211222010181. The next prime is 1211222010329. The reversal of 1211222010221 is 1220102221121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1203981702121 + 7240308100 = 1097261^2 + 85090^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211222010221 - 2³⁰ = 1210148268397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211222010221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211222010421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605611005110 + 605611005111.

It is an arithmetic number, because the mean of its divisors is an integer number (605611005111).

Almost surely, 2^{1211222010221} is an apocalyptic number.

It is an amenable number.

1211222010221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211222010221 is an equidigital number, since it uses as much as digits as its factorization.

1211222010221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1211222010221 its reverse (1220102221121), we get a palindrome (2431324231342).

The spelling of 1211222010221 in words is "one trillion, two hundred eleven billion, two hundred twenty-two million, ten thousand, two hundred twenty-one".