212100011021221 has 8 divisors (see below), whose sum is σ = 214254696240504. Its totient is φ = 209946398059200.

The previous prime is 212100011021201. The next prime is 212100011021251. The reversal of 212100011021221 is 122120110001212.

It can be written as a sum of positive squares in 4 ways, for example, as 120335853852900 + 91764157168321 = 10969770^2 + 9579361^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212100011021221 - 2¹¹ = 212100011019173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212100011021195 and 212100011021204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212100011021201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 267666690 + ... + 268457923.

It is an arithmetic number, because the mean of its divisors is an integer number (26781837030063).

Almost surely, 2^{212100011021221} is an apocalyptic number.

It is an amenable number.

212100011021221 is a deficient number, since it is larger than the sum of its proper divisors (2154685219283).

212100011021221 is a wasteful number, since it uses less digits than its factorization.

212100011021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536128631.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 212100011021221 its reverse (122120110001212), we get a palindrome (334220121022433).

The spelling of 212100011021221 in words is "two hundred twelve trillion, one hundred billion, eleven million, twenty-one thousand, two hundred twenty-one".