221001100221 has 16 divisors (see below), whose sum is σ = 322736859648. Its totient is φ = 133406430000.

The previous prime is 221001100183. The next prime is 221001100231. The reversal of 221001100221 is 122001100122.

It is not a de Polignac number, because 221001100221 - 2¹⁵ = 221001067453 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221001100197 and 221001100206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001100231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13332361 + ... + 13348926.

It is an arithmetic number, because the mean of its divisors is an integer number (20171053728).

Almost surely, 2^221001100221 is an apocalyptic number.

It is an amenable number.

221001100221 is a deficient number, since it is larger than the sum of its proper divisors (101735759427).

221001100221 is a wasteful number, since it uses less digits than its factorization.

221001100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26681552.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 221001100221 its reverse (122001100122), we get a palindrome (343002200343).

Subtracting from 221001100221 its reverse (122001100122), we obtain a palindrome (99000000099).

The spelling of 221001100221 in words is "two hundred twenty-one billion, one million, one hundred thousand, two hundred twenty-one".