211221030101021 has 2 divisors, whose sum is σ = 211221030101022. Its totient is φ = 211221030101020.

The previous prime is 211221030101017. The next prime is 211221030101063. The reversal of 211221030101021 is 120101030122112.

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., 207073539002500 + 4147491098521 = 14390050^2 + 2036539^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221030101021 - 2² = 211221030101017 is a prime.

It is a super-2 number, since 2×211221030101021² (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 (211221030101821) 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, 105610515050510 + 105610515050511.

It is an arithmetic number, because the mean of its divisors is an integer number (105610515050511).

Almost surely, 2^{211221030101021} is an apocalyptic number.

It is an amenable number.

211221030101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221030101021 is an equidigital number, since it uses as much as digits as its factorization.

211221030101021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 211221030101021 its reverse (120101030122112), we get a palindrome (331322060223133).

The spelling of 211221030101021 in words is "two hundred eleven trillion, two hundred twenty-one billion, thirty million, one hundred one thousand, twenty-one".