2131312321 has 4 divisors (see below), whose sum is σ = 2256683652. Its totient is φ = 2005940992.

The previous prime is 2131312303. The next prime is 2131312363. The reversal of 2131312321 is 1232131312.

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 694902321 + 1436410000 = 26361^2 + 37900^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2131312321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2131312021) 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, 62685640 + ... + 62685673.

It is an arithmetic number, because the mean of its divisors is an integer number (564170913).

Almost surely, 2^2131312321 is an apocalyptic number.

It is an amenable number.

2131312321 is a deficient number, since it is larger than the sum of its proper divisors (125371331).

2131312321 is a wasteful number, since it uses less digits than its factorization.

2131312321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125371330.

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

The square root of 2131312321 is about 46166.1382508869. The cubic root of 2131312321 is about 1286.9125372960.

Adding to 2131312321 its reverse (1232131312), we get a palindrome (3363443633).

The spelling of 2131312321 in words is "two billion, one hundred thirty-one million, three hundred twelve thousand, three hundred twenty-one".