2121304221 has 12 divisors (see below), whose sum is σ = 3177591872. Its totient is φ = 1414202652.

The previous prime is 2121304201. The next prime is 2121304223. The reversal of 2121304221 is 1224031212.

It is a happy number.

2121304221 is a `hidden beast` number, since 212 + 1 + 30 + 422 + 1 = 666.

2121304221 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2121304221 - 2¹³ = 2121296029 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 = 2121304194 and 2121304203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121304223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4364581 + ... + 4365066.

Almost surely, 2^2121304221 is an apocalyptic number.

It is an amenable number.

2121304221 is a deficient number, since it is larger than the sum of its proper divisors (1056287651).

2121304221 is an frugal number, since it uses more digits than its factorization.

2121304221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8729662 (or 8729650 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 2121304221 is about 46057.6184903214. The cubic root of 2121304221 is about 1284.8950382354.

Adding to 2121304221 its reverse (1224031212), we get a palindrome (3345335433).

The spelling of 2121304221 in words is "two billion, one hundred twenty-one million, three hundred four thousand, two hundred twenty-one".