221211124021 has 2 divisors, whose sum is σ = 221211124022. Its totient is φ = 221211124020.

The previous prime is 221211124019. The next prime is 221211124031. The reversal of 221211124021 is 120421112122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142816723921 + 78394400100 = 377911^2 + 279990^2 .

It is a cyclic number.

It is not a de Polignac number, because 221211124021 - 2¹ = 221211124019 is a prime.

It is a super-2 number, since 2×221211124021² (a number of 23 digits) contains 22 as substring.

Together with 221211124019, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 221211124021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221211124031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605562010 + 110605562011.

It is an arithmetic number, because the mean of its divisors is an integer number (110605562011).

Almost surely, 2^221211124021 is an apocalyptic number.

It is an amenable number.

221211124021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221211124021 is an equidigital number, since it uses as much as digits as its factorization.

221211124021 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 221211124021 its reverse (120421112122), we get a palindrome (341632236143).

The spelling of 221211124021 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred twenty-four thousand, twenty-one".