2331212221 has 4 divisors (see below), whose sum is σ = 2510536252. Its totient is φ = 2151888192.

The previous prime is 2331212207. The next prime is 2331212237. The reversal of 2331212221 is 1222121332.

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 594823321 + 1736388900 = 24389^2 + 41670^2 .

It is a cyclic number.

It is not a de Polignac number, because 2331212221 - 2⁹ = 2331211709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2331212251) 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, 89661996 + ... + 89662021.

It is an arithmetic number, because the mean of its divisors is an integer number (627634063).

Almost surely, 2^2331212221 is an apocalyptic number.

It is an amenable number.

2331212221 is a deficient number, since it is larger than the sum of its proper divisors (179324031).

2331212221 is a wasteful number, since it uses less digits than its factorization.

2331212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179324030.

The product of its digits is 288, while the sum is 19.

The square root of 2331212221 is about 48282.6285634906. The cubic root of 2331212221 is about 1325.9503747238.

Adding to 2331212221 its reverse (1222121332), we get a palindrome (3553333553).

The spelling of 2331212221 in words is "two billion, three hundred thirty-one million, two hundred twelve thousand, two hundred twenty-one".