111212220221021 has 2 divisors, whose sum is σ = 111212220221022. Its totient is φ = 111212220221020.

The previous prime is 111212220220999. The next prime is 111212220221051. The reversal of 111212220221021 is 120122022212111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96076969156996 + 15135251064025 = 9801886^2 + 3890405^2 .

It is a cyclic number.

It is not a de Polignac number, because 111212220221021 - 2⁶ = 111212220220957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111212220220984 and 111212220221002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111212220221051) 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, 55606110110510 + 55606110110511.

It is an arithmetic number, because the mean of its divisors is an integer number (55606110110511).

Almost surely, 2^{111212220221021} is an apocalyptic number.

It is an amenable number.

111212220221021 is a deficient number, since it is larger than the sum of its proper divisors (1).

111212220221021 is an equidigital number, since it uses as much as digits as its factorization.

111212220221021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 111212220221021 its reverse (120122022212111), we get a palindrome (231334242433132).

The spelling of 111212220221021 in words is "one hundred eleven trillion, two hundred twelve billion, two hundred twenty million, two hundred twenty-one thousand, twenty-one".