31112111021 has 4 divisors (see below), whose sum is σ = 31132702944. Its totient is φ = 31091519100.

The previous prime is 31112111011. The next prime is 31112111029. The reversal of 31112111021 is 12011121113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12011121113 = 89 ⋅134956417.

It is a cyclic number.

It is not a de Polignac number, because 31112111021 - 2⁶ = 31112110957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31112110987 and 31112111005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31112111029) 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, 10293695 + ... + 10296716.

It is an arithmetic number, because the mean of its divisors is an integer number (7783175736).

Almost surely, 2^31112111021 is an apocalyptic number.

It is an amenable number.

31112111021 is a deficient number, since it is larger than the sum of its proper divisors (20591923).

31112111021 is a wasteful number, since it uses less digits than its factorization.

31112111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20591922.

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 31112111021 its reverse (12011121113), we get a palindrome (43123232134).

The spelling of 31112111021 in words is "thirty-one billion, one hundred twelve million, one hundred eleven thousand, twenty-one".