221002212221 has 12 divisors (see below), whose sum is σ = 257999112540. Its totient is φ = 188756326080.

The previous prime is 221002212217. The next prime is 221002212241. The reversal of 221002212221 is 122212200122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 95058139225 + 125944072996 = 308315^2 + 354886^2 .

It is not a de Polignac number, because 221002212221 - 2² = 221002212217 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 221002212221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221002212241) 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, 8011586 + ... + 8039123.

It is an arithmetic number, because the mean of its divisors is an integer number (21499926045).

Almost surely, 2^221002212221 is an apocalyptic number.

It is an amenable number.

221002212221 is a deficient number, since it is larger than the sum of its proper divisors (36996900319).

221002212221 is a wasteful number, since it uses less digits than its factorization.

221002212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16051004 (or 16050997 counting only the distinct ones).

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

Adding to 221002212221 its reverse (122212200122), we get a palindrome (343214412343).

The spelling of 221002212221 in words is "two hundred twenty-one billion, two million, two hundred twelve thousand, two hundred twenty-one".