21111321012 has 24 divisors (see below), whose sum is σ = 49327526976. Its totient is φ = 7027424448.

The previous prime is 21111320977. The next prime is 21111321013. The reversal of 21111321012 is 21012311112.

It is a junction number, because it is equal to n+sod(n) for n = 21111320982 and 21111321000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111321013) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1201233 + ... + 1218680.

It is an arithmetic number, because the mean of its divisors is an integer number (2055313624).

Almost surely, 2^21111321012 is an apocalyptic number.

It is an amenable number.

21111321012 is an abundant number, since it is smaller than the sum of its proper divisors (28216205964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111321012 is a wasteful number, since it uses less digits than its factorization.

21111321012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2420647 (or 2420645 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21111321012 its reverse (21012311112), we get a palindrome (42123632124).

The spelling of 21111321012 in words is "twenty-one billion, one hundred eleven million, three hundred twenty-one thousand, twelve".