221011100121221 has 4 divisors (see below), whose sum is σ = 228140490447744. Its totient is φ = 213881709794700.

The previous prime is 221011100121193. The next prime is 221011100121319. The reversal of 221011100121221 is 122121001110122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221011100121221 - 2¹⁰ = 221011100120197 is a prime.

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 221011100121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221011100171221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3564695163215 + ... + 3564695163276.

It is an arithmetic number, because the mean of its divisors is an integer number (57035122611936).

Almost surely, 2^{221011100121221} is an apocalyptic number.

It is an amenable number.

221011100121221 is a deficient number, since it is larger than the sum of its proper divisors (7129390326523).

221011100121221 is an equidigital number, since it uses as much as digits as its factorization.

221011100121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7129390326522.

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

Adding to 221011100121221 its reverse (122121001110122), we get a palindrome (343132101231343).

The spelling of 221011100121221 in words is "two hundred twenty-one trillion, eleven billion, one hundred million, one hundred twenty-one thousand, two hundred twenty-one".