111221212021 has 2 divisors, whose sum is σ = 111221212022. Its totient is φ = 111221212020.

The previous prime is 111221212013. The next prime is 111221212027. The reversal of 111221212021 is 120212122111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110922302500 + 298909521 = 333050^2 + 17289^2 .

It is a cyclic number.

It is not a de Polignac number, because 111221212021 - 2³ = 111221212013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111221211986 and 111221212004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111221212027) 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, 55610606010 + 55610606011.

It is an arithmetic number, because the mean of its divisors is an integer number (55610606011).

Almost surely, 2^111221212021 is an apocalyptic number.

It is an amenable number.

111221212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

111221212021 is an equidigital number, since it uses as much as digits as its factorization.

111221212021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 111221212021 its reverse (120212122111), we get a palindrome (231433334132).

The spelling of 111221212021 in words is "one hundred eleven billion, two hundred twenty-one million, two hundred twelve thousand, twenty-one".