201100211221221 has 24 divisors (see below), whose sum is σ = 312890247485816. Its totient is φ = 123727195025280.

The previous prime is 201100211221183. The next prime is 201100211221243. The reversal of 201100211221221 is 122122112001102.

201100211221221 is a `hidden beast` number, since 2 + 0 + 1 + 10 + 0 + 211 + 221 + 221 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2149581161025 + 198950630060196 = 1466145^2 + 14104986^2 .

It is not a de Polignac number, because 201100211221221 - 2³⁷ = 200962772267749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201100211221194 and 201100211221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201100211221291) 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, 185436970 + ... + 186518283.

Almost surely, 2^{201100211221221} is an apocalyptic number.

It is an amenable number.

201100211221221 is a deficient number, since it is larger than the sum of its proper divisors (111790036264595).

201100211221221 is a wasteful number, since it uses less digits than its factorization.

201100211221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371959893 (or 371959890 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 201100211221221 its reverse (122122112001102), we get a palindrome (323222323222323).

The spelling of 201100211221221 in words is "two hundred one trillion, one hundred billion, two hundred eleven million, two hundred twenty-one thousand, two hundred twenty-one".