221021201221 has 8 divisors (see below), whose sum is σ = 223116915744. Its totient is φ = 218926044240.

The previous prime is 221021201209. The next prime is 221021201243. The reversal of 221021201221 is 122102120122.

It is a happy number.

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 221021201221 - 2⁹ = 221021200709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221021201195 and 221021201204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021201251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 679926 + ... + 950968.

It is an arithmetic number, because the mean of its divisors is an integer number (27889614468).

Almost surely, 2^221021201221 is an apocalyptic number.

It is an amenable number.

221021201221 is a deficient number, since it is larger than the sum of its proper divisors (2095714523).

221021201221 is a wasteful number, since it uses less digits than its factorization.

221021201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278771.

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

Adding to 221021201221 its reverse (122102120122), we get a palindrome (343123321343).

The spelling of 221021201221 in words is "two hundred twenty-one billion, twenty-one million, two hundred one thousand, two hundred twenty-one".