221012220221 has 4 divisors (see below), whose sum is σ = 238013160252. Its totient is φ = 204011280192.

The previous prime is 221012220217. The next prime is 221012220293. The reversal of 221012220221 is 122022210122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 41245548100 + 179766672121 = 203090^2 + 423989^2 .

It is a cyclic number.

It is not a de Polignac number, because 221012220221 - 2² = 221012220217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 221012220221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221012220721) 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 3 ways as a sum of consecutive naturals, for example, 8500469996 + ... + 8500470021.

It is an arithmetic number, because the mean of its divisors is an integer number (59503290063).

Almost surely, 2^221012220221 is an apocalyptic number.

It is an amenable number.

221012220221 is a deficient number, since it is larger than the sum of its proper divisors (17000940031).

221012220221 is a wasteful number, since it uses less digits than its factorization.

221012220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17000940030.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221012220221 its reverse (122022210122), we get a palindrome (343034430343).

The spelling of 221012220221 in words is "two hundred twenty-one billion, twelve million, two hundred twenty thousand, two hundred twenty-one".