21112111012 has 24 divisors (see below), whose sum is σ = 38229408000. Its totient is φ = 10189598496.

The previous prime is 21112110961. The next prime is 21112111019. The reversal of 21112111012 is 21011121112.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21112110983 and 21112111001.

It is not an unprimeable number, because it can be changed into a prime (21112111019) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518989 + ... + 558187.

It is an arithmetic number, because the mean of its divisors is an integer number (1592892000).

Almost surely, 2^21112111012 is an apocalyptic number.

It is an amenable number.

21112111012 is a deficient number, since it is larger than the sum of its proper divisors (17117296988).

21112111012 is a wasteful number, since it uses less digits than its factorization.

21112111012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43875 (or 43873 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21112111012 its reverse (21011121112), we get a palindrome (42123232124).

The spelling of 21112111012 in words is "twenty-one billion, one hundred twelve million, one hundred eleven thousand, twelve".