211202211221621 has 2 divisors, whose sum is σ = 211202211221622. Its totient is φ = 211202211221620.

The previous prime is 211202211221609. The next prime is 211202211221641. The reversal of 211202211221621 is 126122112202112.

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., 181697216799121 + 29504994422500 = 13479511^2 + 5431850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211202211221621 is a prime.

It is a super-2 number, since 2×211202211221621² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211202211221641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105601105610810 + 105601105610811.

It is an arithmetic number, because the mean of its divisors is an integer number (105601105610811).

Almost surely, 2^{211202211221621} is an apocalyptic number.

It is an amenable number.

211202211221621 is a deficient number, since it is larger than the sum of its proper divisors (1).

211202211221621 is an equidigital number, since it uses as much as digits as its factorization.

211202211221621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 26.

Adding to 211202211221621 its reverse (126122112202112), we get a palindrome (337324323423733).

The spelling of 211202211221621 in words is "two hundred eleven trillion, two hundred two billion, two hundred eleven million, two hundred twenty-one thousand, six hundred twenty-one".