21321213112 has 32 divisors (see below), whose sum is σ = 40300318080. Its totient is φ = 10574534880.

The previous prime is 21321213103. The next prime is 21321213113. The reversal of 21321213112 is 21131212312.

It is a self number, because there is not a number n which added to its sum of digits gives 21321213112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321213113) 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, 4570093 + ... + 4574755.

It is an arithmetic number, because the mean of its divisors is an integer number (1259384940).

Almost surely, 2^21321213112 is an apocalyptic number.

It is an amenable number.

21321213112 is a deficient number, since it is larger than the sum of its proper divisors (18979104968).

21321213112 is a wasteful number, since it uses less digits than its factorization.

21321213112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9163 (or 9159 counting only the distinct ones).

The product of its digits is 144, while the sum is 19.

Adding to 21321213112 its reverse (21131212312), we get a palindrome (42452425424).

The spelling of 21321213112 in words is "twenty-one billion, three hundred twenty-one million, two hundred thirteen thousand, one hundred twelve".