221021101021221 has 12 divisors (see below), whose sum is σ = 319252922608620. Its totient is φ = 147347298619200.

The previous prime is 221021101021199. The next prime is 221021101021247. The reversal of 221021101021221 is 122120101120122.

221021101021221 is a `hidden beast` number, since 2 + 210 + 211 + 0 + 1 + 0 + 21 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 161069374898721 + 59951726122500 = 12691311^2 + 7742850^2 .

It is not a de Polignac number, because 221021101021221 - 2⁶ = 221021101021157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221021101021194 and 221021101021203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021101021621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6627121 + ... + 22044521.

It is an arithmetic number, because the mean of its divisors is an integer number (26604410217385).

Almost surely, 2^{221021101021221} is an apocalyptic number.

It is an amenable number.

221021101021221 is a deficient number, since it is larger than the sum of its proper divisors (98231821587399).

221021101021221 is a wasteful number, since it uses less digits than its factorization.

221021101021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17010276 (or 17010273 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 221021101021221 its reverse (122120101120122), we get a palindrome (343141202141343).

The spelling of 221021101021221 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred one million, twenty-one thousand, two hundred twenty-one".