31831813813 has 4 divisors (see below), whose sum is σ = 32159976940. Its totient is φ = 31503650688.

The previous prime is 31831813787. The next prime is 31831813831.

31831813813 is nontrivially palindromic in base 10.

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 13688532004 + 18143281809 = 116998^2 + 134697^2 .

It is not a de Polignac number, because 31831813813 - 2²⁹ = 31294942901 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 (31831813843) 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, 164081418 + ... + 164081611.

It is an arithmetic number, because the mean of its divisors is an integer number (8039994235).

Almost surely, 2^31831813813 is an apocalyptic number.

It is an amenable number.

31831813813 is a deficient number, since it is larger than the sum of its proper divisors (328163127).

31831813813 is an equidigital number, since it uses as much as digits as its factorization.

31831813813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328163126.

The product of its digits is 41472, while the sum is 40.

The spelling of 31831813813 in words is "thirty-one billion, eight hundred thirty-one million, eight hundred thirteen thousand, eight hundred thirteen".