31011112021 has 4 divisors (see below), whose sum is σ = 31123065772. Its totient is φ = 30899158272.

The previous prime is 31011112009. The next prime is 31011112051. The reversal of 31011112021 is 12021111013.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12021111013 = 74383 ⋅161611.

It can be written as a sum of positive squares in 2 ways, for example, as 8979647121 + 22031464900 = 94761^2 + 148430^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31011112021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31011111992 and 31011112010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31011112001) 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, 55976460 + ... + 55977013.

It is an arithmetic number, because the mean of its divisors is an integer number (7780766443).

Almost surely, 2^31011112021 is an apocalyptic number.

It is an amenable number.

31011112021 is a deficient number, since it is larger than the sum of its proper divisors (111953751).

31011112021 is a wasteful number, since it uses less digits than its factorization.

31011112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111953750.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 31011112021 its reverse (12021111013), we get a palindrome (43032223034).

The spelling of 31011112021 in words is "thirty-one billion, eleven million, one hundred twelve thousand, twenty-one".