221100101211221 has 8 divisors (see below), whose sum is σ = 221468209916184. Its totient is φ = 220732219809280.

The previous prime is 221100101211203. The next prime is 221100101211251. The reversal of 221100101211221 is 122112101001122.

It can be written as a sum of positive squares in 4 ways, for example, as 44464704530596 + 176635396680625 = 6668186^2 + 13290425^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221100101211221 - 2³⁸ = 220825223304277 is a prime.

It is a super-2 number, since 2×221100101211221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221100101211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100101211251) 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 in 7 ways as a sum of consecutive naturals, for example, 54878660 + ... + 58769613.

It is an arithmetic number, because the mean of its divisors is an integer number (27683526239523).

Almost surely, 2^{221100101211221} is an apocalyptic number.

It is an amenable number.

221100101211221 is a deficient number, since it is larger than the sum of its proper divisors (368108704963).

221100101211221 is a wasteful number, since it uses less digits than its factorization.

221100101211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113651511.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 221100101211221 its reverse (122112101001122), we get a palindrome (343212202212343).

The spelling of 221100101211221 in words is "two hundred twenty-one trillion, one hundred billion, one hundred one million, two hundred eleven thousand, two hundred twenty-one".