212121100111121 has 4 divisors (see below), whose sum is σ = 216123385018932. Its totient is φ = 208118815203312.

The previous prime is 212121100111093. The next prime is 212121100111177. The reversal of 212121100111121 is 121111001121212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 157855704196096 + 54265395915025 = 12564064^2 + 7366505^2 .

It is a cyclic number.

It is not a de Polignac number, because 212121100111121 - 2²² = 212121095916817 is a prime.

It is a super-3 number, since 3×212121100111121³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 212121100111121.

It is not an unprimeable number, because it can be changed into a prime (212121100111621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2001142453826 + ... + 2001142453931.

It is an arithmetic number, because the mean of its divisors is an integer number (54030846254733).

Almost surely, 2^{212121100111121} is an apocalyptic number.

It is an amenable number.

212121100111121 is a deficient number, since it is larger than the sum of its proper divisors (4002284907811).

212121100111121 is an equidigital number, since it uses as much as digits as its factorization.

212121100111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4002284907810.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 212121100111121 its reverse (121111001121212), we get a palindrome (333232101232333).

The spelling of 212121100111121 in words is "two hundred twelve trillion, one hundred twenty-one billion, one hundred million, one hundred eleven thousand, one hundred twenty-one".