221221000221 has 24 divisors (see below), whose sum is σ = 337435154784. Its totient is φ = 128127993600.

The previous prime is 221221000199. The next prime is 221221000267. The reversal of 221221000221 is 122000122122.

It is not a de Polignac number, because 221221000221 - 2⁶ = 221221000157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221221000221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221000921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9802455 + ... + 9824996.

It is an arithmetic number, because the mean of its divisors is an integer number (14059798116).

Almost surely, 2^221221000221 is an apocalyptic number.

It is an amenable number.

221221000221 is a deficient number, since it is larger than the sum of its proper divisors (116214154563).

221221000221 is a wasteful number, since it uses less digits than its factorization.

221221000221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19627501 (or 19627484 counting only the distinct ones).

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

Adding to 221221000221 its reverse (122000122122), we get a palindrome (343221122343).

The spelling of 221221000221 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-one", and thus it is an aban number.