221221222011 has 16 divisors (see below), whose sum is σ = 328072705920. Its totient is φ = 147328911720.

The previous prime is 221221221997. The next prime is 221221222031. The reversal of 221221222011 is 110222122122.

It is a happy number.

221221222011 is a `hidden beast` number, since 221 + 2 + 212 + 220 + 11 = 666.

It is not a de Polignac number, because 221221222011 - 2¹³ = 221221213819 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221221222031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4192825 + ... + 4245258.

It is an arithmetic number, because the mean of its divisors is an integer number (20504544120).

Almost surely, 2^221221222011 is an apocalyptic number.

221221222011 is a deficient number, since it is larger than the sum of its proper divisors (106851483909).

221221222011 is an equidigital number, since it uses as much as digits as its factorization.

221221222011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8439063 (or 8439057 counting only the distinct ones).

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

Adding to 221221222011 its reverse (110222122122), we get a palindrome (331443344133).

The spelling of 221221222011 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-two thousand, eleven".