221210221221 has 24 divisors (see below), whose sum is σ = 348861236256. Its totient is φ = 133956203040.

The previous prime is 221210221217. The next prime is 221210221229. The reversal of 221210221221 is 122122012122.

It is a happy number.

221210221221 is a `hidden beast` number, since 2 + 212 + 10 + 221 + 221 = 666.

It is not a de Polignac number, because 221210221221 - 2² = 221210221217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221210221194 and 221210221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221210221229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 800955 + ... + 1041128.

It is an arithmetic number, because the mean of its divisors is an integer number (14535884844).

Almost surely, 2^221210221221 is an apocalyptic number.

It is an amenable number.

221210221221 is a deficient number, since it is larger than the sum of its proper divisors (127651015035).

221210221221 is a wasteful number, since it uses less digits than its factorization.

221210221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1843313 (or 1843310 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221210221221 its reverse (122122012122), we get a palindrome (343332233343).

The spelling of 221210221221 in words is "two hundred twenty-one billion, two hundred ten million, two hundred twenty-one thousand, two hundred twenty-one".