31123313211 has 4 divisors (see below), whose sum is σ = 41497750952. Its totient is φ = 20748875472.

The previous prime is 31123313209. The next prime is 31123313219. The reversal of 31123313211 is 11231332113.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 31123313211 - 2¹ = 31123313209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31123313219) 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, 5187218866 + ... + 5187218871.

It is an arithmetic number, because the mean of its divisors is an integer number (10374437738).

Almost surely, 2^31123313211 is an apocalyptic number.

31123313211 is a deficient number, since it is larger than the sum of its proper divisors (10374437741).

31123313211 is a wasteful number, since it uses less digits than its factorization.

31123313211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10374437740.

The product of its digits is 324, while the sum is 21.

Adding to 31123313211 its reverse (11231332113), we get a palindrome (42354645324).

The spelling of 31123313211 in words is "thirty-one billion, one hundred twenty-three million, three hundred thirteen thousand, two hundred eleven".