2121324221 has 4 divisors (see below), whose sum is σ = 2122401372. Its totient is φ = 2120247072.

The previous prime is 2121324211. The next prime is 2121324223. The reversal of 2121324221 is 1224231212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 676260025 + 1445064196 = 26005^2 + 38014^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121324221 - 2⁶ = 2121324157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121324193 and 2121324202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121324223) 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, 535616 + ... + 539561.

It is an arithmetic number, because the mean of its divisors is an integer number (530600343).

Almost surely, 2^2121324221 is an apocalyptic number.

It is an amenable number.

2121324221 is a deficient number, since it is larger than the sum of its proper divisors (1077151).

2121324221 is a wasteful number, since it uses less digits than its factorization.

2121324221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077150.

The product of its digits is 384, while the sum is 20.

The square root of 2121324221 is about 46057.8356091556. The cubic root of 2121324221 is about 1284.8990762889.

Adding to 2121324221 its reverse (1224231212), we get a palindrome (3345555433).

The spelling of 2121324221 in words is "two billion, one hundred twenty-one million, three hundred twenty-four thousand, two hundred twenty-one".