212121011011221 has 18 divisors (see below), whose sum is σ = 331779017225058. Its totient is φ = 130536006775200.

The previous prime is 212121011011201. The next prime is 212121011011243. The reversal of 212121011011221 is 122110110121212.

It is a happy number.

212121011011221 is a `hidden beast` number, since 2 + 121 + 210 + 110 + 1 + 1 + 221 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 17766351450225 + 194354659560996 = 4215015^2 + 13941114^2 .

It is not a de Polignac number, because 212121011011221 - 2¹⁹ = 212121010486933 is a prime.

It is a super-3 number, since 3×212121011011221³ (a number of 44 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 212121011011194 and 212121011011203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121011011201) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 69730771330 + ... + 69730774371.

Almost surely, 2^{212121011011221} is an apocalyptic number.

It is an amenable number.

212121011011221 is a deficient number, since it is larger than the sum of its proper divisors (119658006213837).

212121011011221 is a wasteful number, since it uses less digits than its factorization.

212121011011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139461545733 (or 139461545717 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 212121011011221 its reverse (122110110121212), we get a palindrome (334231121132433).

The spelling of 212121011011221 in words is "two hundred twelve trillion, one hundred twenty-one billion, eleven million, eleven thousand, two hundred twenty-one".