221211112021 has 2 divisors, whose sum is σ = 221211112022. Its totient is φ = 221211112020.

The previous prime is 221211112009. The next prime is 221211112091. The reversal of 221211112021 is 120211112122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168120500625 + 53090611396 = 410025^2 + 230414^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221211112021 is a prime.

It is a super-3 number, since 3×221211112021³ (a number of 35 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221211111986 and 221211112004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221211112091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605556010 + 110605556011.

It is an arithmetic number, because the mean of its divisors is an integer number (110605556011).

Almost surely, 2^221211112021 is an apocalyptic number.

It is an amenable number.

221211112021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221211112021 is an equidigital number, since it uses as much as digits as its factorization.

221211112021 is an evil number, because the sum of its binary digits is even.

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

Adding to 221211112021 its reverse (120211112122), we get a palindrome (341422224143).

The spelling of 221211112021 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred twelve thousand, twenty-one".