212221220121 has 6 divisors (see below), whose sum is σ = 306541762410. Its totient is φ = 141480813408.

The previous prime is 212221220093. The next prime is 212221220177. The reversal of 212221220121 is 121022122212.

It is a happy number.

212221220121 is a `hidden beast` number, since 212 + 221 + 220 + 12 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 205209000000 + 7012220121 = 453000^2 + 83739^2 .

It is not a de Polignac number, because 212221220121 - 2⁵ = 212221220089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212221220094 and 212221220103.

It is not an unprimeable number, because it can be changed into a prime (212221220191) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11790067776 + ... + 11790067793.

It is an arithmetic number, because the mean of its divisors is an integer number (51090293735).

Almost surely, 2^212221220121 is an apocalyptic number.

It is an amenable number.

212221220121 is a deficient number, since it is larger than the sum of its proper divisors (94320542289).

212221220121 is a wasteful number, since it uses less digits than its factorization.

212221220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23580135575 (or 23580135572 counting only the distinct ones).

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

Adding to 212221220121 its reverse (121022122212), we get a palindrome (333243342333).

The spelling of 212221220121 in words is "two hundred twelve billion, two hundred twenty-one million, two hundred twenty thousand, one hundred twenty-one".