221200020001221 has 16 divisors (see below), whose sum is σ = 296639140584960. Its totient is φ = 146613795247040.

The previous prime is 221200020001199. The next prime is 221200020001277. The reversal of 221200020001221 is 122100020002122.

It is a cyclic number.

It is not a de Polignac number, because 221200020001221 - 2¹¹ = 221200019999173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221200020001221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221200020001621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 239431660 + ... + 240353738.

It is an arithmetic number, because the mean of its divisors is an integer number (18539946286560).

Almost surely, 2^{221200020001221} is an apocalyptic number.

It is an amenable number.

221200020001221 is a deficient number, since it is larger than the sum of its proper divisors (75439120583739).

221200020001221 is a wasteful number, since it uses less digits than its factorization.

221200020001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1384476.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221200020001221 its reverse (122100020002122), we get a palindrome (343300040003343).

Subtracting from 221200020001221 its reverse (122100020002122), we obtain a palindrome (99099999999099).

The spelling of 221200020001221 in words is "two hundred twenty-one trillion, two hundred billion, twenty million, one thousand, two hundred twenty-one".