221021012221 has 12 divisors (see below), whose sum is σ = 244995165792. Its totient is φ = 198975432128.

The previous prime is 221021012203. The next prime is 221021012249. The reversal of 221021012221 is 122210120122.

It is a happy number.

It is not a de Polignac number, because 221021012221 - 2¹⁷ = 221020881149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221021012195 and 221021012204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021012021) 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, 16618975 + ... + 16632268.

It is an arithmetic number, because the mean of its divisors is an integer number (20416263816).

Almost surely, 2^221021012221 is an apocalyptic number.

It is an amenable number.

221021012221 is a deficient number, since it is larger than the sum of its proper divisors (23974153571).

221021012221 is a wasteful number, since it uses less digits than its factorization.

221021012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33251300 (or 33251283 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221021012221 its reverse (122210120122), we get a palindrome (343231132343).

The spelling of 221021012221 in words is "two hundred twenty-one billion, twenty-one million, twelve thousand, two hundred twenty-one".