221021112121081 has 2 divisors, whose sum is σ = 221021112121082. Its totient is φ = 221021112121080.

The previous prime is 221021112121009. The next prime is 221021112121129. The reversal of 221021112121081 is 180121211120122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192912654490000 + 28108457631081 = 13889300^2 + 5301741^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021112121081 - 2³⁷ = 220883673167609 is a prime.

It is a super-3 number, since 3×221021112121081³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (221021112121001) 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, 110510556060540 + 110510556060541.

It is an arithmetic number, because the mean of its divisors is an integer number (110510556060541).

Almost surely, 2^{221021112121081} is an apocalyptic number.

It is an amenable number.

221021112121081 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021112121081 is an equidigital number, since it uses as much as digits as its factorization.

221021112121081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 25.

The spelling of 221021112121081 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred twelve million, one hundred twenty-one thousand, eighty-one".