21111020012 has 12 divisors (see below), whose sum is σ = 36991233720. Its totient is φ = 10542096096.

The previous prime is 21111020009. The next prime is 21111020039. The reversal of 21111020012 is 21002011112.

It is a junction number, because it is equal to n+sod(n) for n = 21111019975 and 21111020002.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3349937 + ... + 3356232.

It is an arithmetic number, because the mean of its divisors is an integer number (3082602810).

Almost surely, 2^21111020012 is an apocalyptic number.

It is an amenable number.

21111020012 is a deficient number, since it is larger than the sum of its proper divisors (15880213708).

21111020012 is a wasteful number, since it uses less digits than its factorization.

21111020012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6706960 (or 6706958 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21111020012 its reverse (21002011112), we get a palindrome (42113031124).

The spelling of 21111020012 in words is "twenty-one billion, one hundred eleven million, twenty thousand, twelve".