212121010101221 has 8 divisors (see below), whose sum is σ = 232748162027640. Its totient is φ = 192109594053312.

The previous prime is 212121010101149. The next prime is 212121010101227. The reversal of 212121010101221 is 122101010121212.

It can be written as a sum of positive squares in 4 ways, for example, as 5550500402500 + 206570509698721 = 2355950^2 + 14372561^2 .

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

It is not a de Polignac number, because 212121010101221 - 2²² = 212121005906917 is a prime.

It is a super-3 number, since 3×212121010101221³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212121010101221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121010101227) 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, 153933968906 + ... + 153933970283.

It is an arithmetic number, because the mean of its divisors is an integer number (29093520253455).

Almost surely, 2^{212121010101221} is an apocalyptic number.

It is an amenable number.

212121010101221 is a deficient number, since it is larger than the sum of its proper divisors (20627151926419).

212121010101221 is a wasteful number, since it uses less digits than its factorization.

212121010101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307867939255.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 212121010101221 its reverse (122101010121212), we get a palindrome (334222020222433).

The spelling of 212121010101221 in words is "two hundred twelve trillion, one hundred twenty-one billion, ten million, one hundred one thousand, two hundred twenty-one".