212121100222121 has 4 divisors (see below), whose sum is σ = 216634315120512. Its totient is φ = 207607885323732.

The previous prime is 212121100222067. The next prime is 212121100222189. The reversal of 212121100222121 is 121222001121212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212121100222121 - 2¹⁰ = 212121100221097 is a prime.

It is a super-3 number, since 3×212121100222121³ (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 junction number, because it is equal to n+sod(n) for n = 212121100222093 and 212121100222102.

It is not an unprimeable number, because it can be changed into a prime (212121100227121) 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, 2256607449125 + ... + 2256607449218.

It is an arithmetic number, because the mean of its divisors is an integer number (54158578780128).

Almost surely, 2^{212121100222121} is an apocalyptic number.

It is an amenable number.

212121100222121 is a deficient number, since it is larger than the sum of its proper divisors (4513214898391).

212121100222121 is an equidigital number, since it uses as much as digits as its factorization.

212121100222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4513214898390.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 212121100222121 its reverse (121222001121212), we get a palindrome (333343101343333).

The spelling of 212121100222121 in words is "two hundred twelve trillion, one hundred twenty-one billion, one hundred million, two hundred twenty-two thousand, one hundred twenty-one".