2121022121 has 4 divisors (see below), whose sum is σ = 2150895744. Its totient is φ = 2091148500.

The previous prime is 2121022109. The next prime is 2121022129. The reversal of 2121022121 is 1212201212.

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 a de Polignac number, because none of the positive numbers 2^k-2121022121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2121022096 and 2121022105.

It is not an unprimeable number, because it can be changed into a prime (2121022129) 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, 14936705 + ... + 14936846.

It is an arithmetic number, because the mean of its divisors is an integer number (537723936).

Almost surely, 2^2121022121 is an apocalyptic number.

It is an amenable number.

2121022121 is a deficient number, since it is larger than the sum of its proper divisors (29873623).

2121022121 is an equidigital number, since it uses as much as digits as its factorization.

2121022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29873622.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 2121022121 is about 46054.5559201259. Note that the first 3 decimals coincide. The cubic root of 2121022121 is about 1284.8380787864.

Adding to 2121022121 its reverse (1212201212), we get a palindrome (3333223333).

The spelling of 2121022121 in words is "two billion, one hundred twenty-one million, twenty-two thousand, one hundred twenty-one".