221001101021221 has 4 divisors (see below), whose sum is σ = 221173354413792. Its totient is φ = 220828847628652.

The previous prime is 221001101021177. The next prime is 221001101021231. The reversal of 221001101021221 is 122120101100122.

221001101021221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 221001101021221 - 2²³ = 221001092632613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221001101021195 and 221001101021204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001101021231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86126694361 + ... + 86126696926.

It is an arithmetic number, because the mean of its divisors is an integer number (55293338603448).

Almost surely, 2^{221001101021221} is an apocalyptic number.

It is an amenable number.

221001101021221 is a deficient number, since it is larger than the sum of its proper divisors (172253392571).

221001101021221 is a wasteful number, since it uses less digits than its factorization.

221001101021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172253392570.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 221001101021221 its reverse (122120101100122), we get a palindrome (343121202121343).

The spelling of 221001101021221 in words is "two hundred twenty-one trillion, one billion, one hundred one million, twenty-one thousand, two hundred twenty-one".