31121113211 has 4 divisors (see below), whose sum is σ = 31122078624. Its totient is φ = 31120147800.

The previous prime is 31121113169. The next prime is 31121113241. The reversal of 31121113211 is 11231112113.

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

It is a cyclic number.

It is not a de Polignac number, because 31121113211 - 2⁶ = 31121113147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31121113211.

It is not an unprimeable number, because it can be changed into a prime (31121113241) 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, 432620 + ... + 499401.

It is an arithmetic number, because the mean of its divisors is an integer number (7780519656).

Almost surely, 2^31121113211 is an apocalyptic number.

31121113211 is a deficient number, since it is larger than the sum of its proper divisors (965413).

31121113211 is an equidigital number, since it uses as much as digits as its factorization.

31121113211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 965412.

The product of its digits is 36, while the sum is 17.

Adding to 31121113211 its reverse (11231112113), we get a palindrome (42352225324).

The spelling of 31121113211 in words is "thirty-one billion, one hundred twenty-one million, one hundred thirteen thousand, two hundred eleven".