2131323221 has 4 divisors (see below), whose sum is σ = 2223989472. Its totient is φ = 2038656972.

The previous prime is 2131323217. The next prime is 2131323281. The reversal of 2131323221 is 1223231312.

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 not a de Polignac number, because 2131323221 - 2² = 2131323217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2131323193 and 2131323202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2131323281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46333091 + ... + 46333136.

It is an arithmetic number, because the mean of its divisors is an integer number (555997368).

Almost surely, 2^2131323221 is an apocalyptic number.

It is an amenable number.

2131323221 is a deficient number, since it is larger than the sum of its proper divisors (92666251).

2131323221 is an equidigital number, since it uses as much as digits as its factorization.

2131323221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92666250.

The product of its digits is 432, while the sum is 20.

The square root of 2131323221 is about 46166.2563026287. The cubic root of 2131323221 is about 1286.9147311435.

Adding to 2131323221 its reverse (1223231312), we get a palindrome (3354554533).

The spelling of 2131323221 in words is "two billion, one hundred thirty-one million, three hundred twenty-three thousand, two hundred twenty-one".