31131122011 has 4 divisors (see below), whose sum is σ = 33961224024. Its totient is φ = 28301020000.

The previous prime is 31131121999. The next prime is 31131122017. The reversal of 31131122011 is 11022113113.

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 31131122011 - 2⁷ = 31131121883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31131122017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1415050990 + ... + 1415051011.

It is an arithmetic number, because the mean of its divisors is an integer number (8490306006).

Almost surely, 2^31131122011 is an apocalyptic number.

31131122011 is a deficient number, since it is larger than the sum of its proper divisors (2830102013).

31131122011 is a wasteful number, since it uses less digits than its factorization.

31131122011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2830102012.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 31131122011 its reverse (11022113113), we get a palindrome (42153235124).

The spelling of 31131122011 in words is "thirty-one billion, one hundred thirty-one million, one hundred twenty-two thousand, eleven".