221200121220521 has 2 divisors, whose sum is σ = 221200121220522. Its totient is φ = 221200121220520.

The previous prime is 221200121220503. The next prime is 221200121220527. The reversal of 221200121220521 is 125022121002122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129691554768400 + 91508566452121 = 11388220^2 + 9566011^2 .

It is a cyclic number.

It is not a de Polignac number, because 221200121220521 - 2⁶ = 221200121220457 is a prime.

It is a super-2 number, since 2×221200121220521² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221200121220527) 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, 110600060610260 + 110600060610261.

It is an arithmetic number, because the mean of its divisors is an integer number (110600060610261).

Almost surely, 2^{221200121220521} is an apocalyptic number.

It is an amenable number.

221200121220521 is a deficient number, since it is larger than the sum of its proper divisors (1).

221200121220521 is an equidigital number, since it uses as much as digits as its factorization.

221200121220521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 23.

Adding to 221200121220521 its reverse (125022121002122), we get a palindrome (346222242222643).

The spelling of 221200121220521 in words is "two hundred twenty-one trillion, two hundred billion, one hundred twenty-one million, two hundred twenty thousand, five hundred twenty-one".