31320203213 has 4 divisors (see below), whose sum is σ = 33729449628. Its totient is φ = 28910956800.

The previous prime is 31320203183. The next prime is 31320203227. The reversal of 31320203213 is 31230202313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31230202313 = 359 ⋅86992207.

It can be written as a sum of positive squares in 2 ways, for example, as 1543939849 + 29776263364 = 39293^2 + 172558^2 .

It is a cyclic number.

It is not a de Polignac number, because 31320203213 - 2¹⁰ = 31320202189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31320203263) 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, 1204623188 + ... + 1204623213.

It is an arithmetic number, because the mean of its divisors is an integer number (8432362407).

Almost surely, 2^31320203213 is an apocalyptic number.

It is an amenable number.

31320203213 is a deficient number, since it is larger than the sum of its proper divisors (2409246415).

31320203213 is a wasteful number, since it uses less digits than its factorization.

31320203213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2409246414.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 31320203213 its reverse (31230202313), we get a palindrome (62550405526).

The spelling of 31320203213 in words is "thirty-one billion, three hundred twenty million, two hundred three thousand, two hundred thirteen".