211231121102821 has 2 divisors, whose sum is σ = 211231121102822. Its totient is φ = 211231121102820.

The previous prime is 211231121102801. The next prime is 211231121102851. The reversal of 211231121102821 is 128201121132112.

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., 173358038902500 + 37873082200321 = 13166550^2 + 6154111^2 .

It is a cyclic number.

It is not a de Polignac number, because 211231121102821 - 2⁴³ = 202435028080613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211231121102821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211231121102801) 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, 105615560551410 + 105615560551411.

It is an arithmetic number, because the mean of its divisors is an integer number (105615560551411).

Almost surely, 2^{211231121102821} is an apocalyptic number.

It is an amenable number.

211231121102821 is a deficient number, since it is larger than the sum of its proper divisors (1).

211231121102821 is an equidigital number, since it uses as much as digits as its factorization.

211231121102821 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 28.

Adding to 211231121102821 its reverse (128201121132112), we get a palindrome (339432242234933).

The spelling of 211231121102821 in words is "two hundred eleven trillion, two hundred thirty-one billion, one hundred twenty-one million, one hundred two thousand, eight hundred twenty-one".