221212210011221 has 16 divisors (see below), whose sum is σ = 259993465357248. Its totient is φ = 185555629459200.

The previous prime is 221212210011209. The next prime is 221212210011227. The reversal of 221212210011221 is 122110012212122.

221212210011221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221212210011221 - 2¹⁴ = 221212209994837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221212210011193 and 221212210011202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212210011227) 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, 320463716 + ... + 321153261.

It is an arithmetic number, because the mean of its divisors is an integer number (16249591584828).

Almost surely, 2^{221212210011221} is an apocalyptic number.

It is an amenable number.

221212210011221 is a deficient number, since it is larger than the sum of its proper divisors (38781255346027).

221212210011221 is a wasteful number, since it uses less digits than its factorization.

221212210011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641619412.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 221212210011221 its reverse (122110012212122), we get a palindrome (343322222223343).

The spelling of 221212210011221 in words is "two hundred twenty-one trillion, two hundred twelve billion, two hundred ten million, eleven thousand, two hundred twenty-one".