21112110031 has 2 divisors, whose sum is σ = 21112110032. Its totient is φ = 21112110030.

The previous prime is 21112109999. The next prime is 21112110037. The reversal of 21112110031 is 13001121112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21112110031 - 2⁵ = 21112109999 is a prime.

It is a super-2 number, since 2×21112110031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21112109993 and 21112110020.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112110037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556055015 + 10556055016.

It is an arithmetic number, because the mean of its divisors is an integer number (10556055016).

Almost surely, 2^21112110031 is an apocalyptic number.

21112110031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112110031 is an equidigital number, since it uses as much as digits as its factorization.

21112110031 is an evil number, because the sum of its binary digits is even.

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

Adding to 21112110031 its reverse (13001121112), we get a palindrome (34113231143).

The spelling of 21112110031 in words is "twenty-one billion, one hundred twelve million, one hundred ten thousand, thirty-one".