212121001210221 has 12 divisors (see below), whose sum is σ = 306397456737372. Its totient is φ = 141413790811776.

The previous prime is 212121001210211. The next prime is 212121001210289. The reversal of 212121001210221 is 122012100121212.

212121001210221 is a `hidden beast` number, since 2 + 1 + 21 + 210 + 0 + 1 + 210 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 146591895260196 + 65529105950025 = 12107514^2 + 8095005^2 .

It is not a de Polignac number, because 212121001210221 - 2⁵ = 212121001210189 is a prime.

It is a super-3 number, since 3×212121001210221³ (a number of 44 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 212121001210194 and 212121001210203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121001210211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10974066 + ... + 23338211.

It is an arithmetic number, because the mean of its divisors is an integer number (25533121394781).

Almost surely, 2^{212121001210221} is an apocalyptic number.

It is an amenable number.

212121001210221 is a deficient number, since it is larger than the sum of its proper divisors (94276455527151).

212121001210221 is a wasteful number, since it uses less digits than its factorization.

212121001210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34999180 (or 34999177 counting only the distinct ones).

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

Adding to 212121001210221 its reverse (122012100121212), we get a palindrome (334133101331433).

The spelling of 212121001210221 in words is "two hundred twelve trillion, one hundred twenty-one billion, one million, two hundred ten thousand, two hundred twenty-one".