221221202020171 has 2 divisors, whose sum is σ = 221221202020172. Its totient is φ = 221221202020170.

The previous prime is 221221202020141. The next prime is 221221202020229. The reversal of 221221202020171 is 171020202122122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221221202020171 - 2⁵ = 221221202020139 is a prime.

It is not a weakly prime, because it can be changed into another prime (221221202020141) 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, 110610601010085 + 110610601010086.

It is an arithmetic number, because the mean of its divisors is an integer number (110610601010086).

Almost surely, 2^{221221202020171} is an apocalyptic number.

221221202020171 is a deficient number, since it is larger than the sum of its proper divisors (1).

221221202020171 is an equidigital number, since it uses as much as digits as its factorization.

221221202020171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 25.

Adding to 221221202020171 its reverse (171020202122122), we get a palindrome (392241404142293).

The spelling of 221221202020171 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, two hundred two million, twenty thousand, one hundred seventy-one".