221111222020021 has 2 divisors, whose sum is σ = 221111222020022. Its totient is φ = 221111222020020.

The previous prime is 221111222019983. The next prime is 221111222020049. The reversal of 221111222020021 is 120020222111122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210864116787921 + 10247105232100 = 14521161^2 + 3201110^2 .

It is a cyclic number.

It is not a de Polignac number, because 221111222020021 - 2³¹ = 221109074536373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221111222020621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110555611010010 + 110555611010011.

It is an arithmetic number, because the mean of its divisors is an integer number (110555611010011).

Almost surely, 2^{221111222020021} is an apocalyptic number.

It is an amenable number.

221111222020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221111222020021 is an equidigital number, since it uses as much as digits as its factorization.

221111222020021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 221111222020021 its reverse (120020222111122), we get a palindrome (341131444131143).

The spelling of 221111222020021 in words is "two hundred twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, twenty thousand, twenty-one".