2121002121 has 24 divisors (see below), whose sum is σ = 3264649792. Its totient is φ = 1199880000.

The previous prime is 2121002101. The next prime is 2121002123. The reversal of 2121002121 is 1212001212.

It is not a de Polignac number, because 2121002121 - 2¹⁹ = 2120477833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121002097 and 2121002106.

It is not an unprimeable number, because it can be changed into a prime (2121002123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 209271 + ... + 219171.

Almost surely, 2^2121002121 is an apocalyptic number.

2121002121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2121002121 is a deficient number, since it is larger than the sum of its proper divisors (1143647671).

2121002121 is an equidigital number, since it uses as much as digits as its factorization.

2121002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10113 (or 10012 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 2121002121 is about 46054.3387858299. The cubic root of 2121002121 is about 1284.8340403494.

Multiplying 2121002121 by its sum of digits (12), we get a palindrome (25452025452).

Adding to 2121002121 its reverse (1212001212), we get a palindrome (3333003333).

Subtracting from 2121002121 its reverse (1212001212), we obtain a palindrome (909000909).

It can be divided in two parts, 212100 and 2121, that multiplied together give a square (449864100 = 21210²).

The spelling of 2121002121 in words is "two billion, one hundred twenty-one million, two thousand, one hundred twenty-one".