221012208121 has 2 divisors, whose sum is σ = 221012208122. Its totient is φ = 221012208120.

The previous prime is 221012208119. The next prime is 221012208127. The reversal of 221012208121 is 121802210122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134538572025 + 86473636096 = 366795^2 + 294064^2 .

It is a cyclic number.

It is not a de Polignac number, because 221012208121 - 2¹ = 221012208119 is a prime.

It is a super-2 number, since 2×221012208121² (a number of 23 digits) contains 22 as substring.

Together with 221012208119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 221012208092 and 221012208101.

It is not a weakly prime, because it can be changed into another prime (221012208127) 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, 110506104060 + 110506104061.

It is an arithmetic number, because the mean of its divisors is an integer number (110506104061).

Almost surely, 2^221012208121 is an apocalyptic number.

It is an amenable number.

221012208121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221012208121 is an equidigital number, since it uses as much as digits as its factorization.

221012208121 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 22.

Adding to 221012208121 its reverse (121802210122), we get a palindrome (342814418243).

The spelling of 221012208121 in words is "two hundred twenty-one billion, twelve million, two hundred eight thousand, one hundred twenty-one".