2112121212221 has 4 divisors (see below), whose sum is σ = 2114419495200. Its totient is φ = 2109822929244.

The previous prime is 2112121212217. The next prime is 2112121212263. The reversal of 2112121212221 is 1222121212112.

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 2112121212221 - 2² = 2112121212217 is a prime.

It is a super-2 number, since 2×2112121212221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2112121212193 and 2112121212202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2112121212121) 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, 1149140111 + ... + 1149141948.

It is an arithmetic number, because the mean of its divisors is an integer number (528604873800).

Almost surely, 2^{2112121212221} is an apocalyptic number.

It is an amenable number.

2112121212221 is a deficient number, since it is larger than the sum of its proper divisors (2298282979).

2112121212221 is an equidigital number, since it uses as much as digits as its factorization.

2112121212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2298282978.

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

Adding to 2112121212221 its reverse (1222121212112), we get a palindrome (3334242424333).

The spelling of 2112121212221 in words is "two trillion, one hundred twelve billion, one hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".