31312211111 has 4 divisors (see below), whose sum is σ = 31414205592. Its totient is φ = 31210216632.

The previous prime is 31312211089. The next prime is 31312211129. The reversal of 31312211111 is 11111221313.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31312211111 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 31312211111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31312211911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50996780 + ... + 50997393.

It is an arithmetic number, because the mean of its divisors is an integer number (7853551398).

Almost surely, 2^31312211111 is an apocalyptic number.

31312211111 is a deficient number, since it is larger than the sum of its proper divisors (101994481).

31312211111 is a wasteful number, since it uses less digits than its factorization.

31312211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101994480.

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

Adding to 31312211111 its reverse (11111221313), we get a palindrome (42423432424).

The spelling of 31312211111 in words is "thirty-one billion, three hundred twelve million, two hundred eleven thousand, one hundred eleven".