2131313221 has 8 divisors (see below), whose sum is σ = 2207128824. Its totient is φ = 2056816320.

The previous prime is 2131313161. The next prime is 2131313279. The reversal of 2131313221 is 1223131312.

It can be written as a sum of positive squares in 4 ways, for example, as 14025025 + 2117288196 = 3745^2 + 46014^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2131313221 - 2⁹ = 2131312709 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 (2131113221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 326386 + ... + 332851.

It is an arithmetic number, because the mean of its divisors is an integer number (275891103).

Almost surely, 2^2131313221 is an apocalyptic number.

It is an amenable number.

2131313221 is a deficient number, since it is larger than the sum of its proper divisors (75815603).

2131313221 is an equidigital number, since it uses as much as digits as its factorization.

2131313221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659351.

The product of its digits is 216, while the sum is 19.

The square root of 2131313221 is about 46166.1479982898. The cubic root of 2131313221 is about 1286.9127184396.

Adding to 2131313221 its reverse (1223131312), we get a palindrome (3354444533).

The spelling of 2131313221 in words is "two billion, one hundred thirty-one million, three hundred thirteen thousand, two hundred twenty-one".