21323112012 has 36 divisors (see below), whose sum is σ = 54549495000. Its totient is φ = 7022068032.

The previous prime is 21323111989. The next prime is 21323112071. The reversal of 21323112012 is 21021132312.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3565137 + ... + 3571112.

It is an arithmetic number, because the mean of its divisors is an integer number (1515263750).

Almost surely, 2^21323112012 is an apocalyptic number.

It is an amenable number.

21323112012 is an abundant number, since it is smaller than the sum of its proper divisors (33226382988).

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

21323112012 is a wasteful number, since it uses less digits than its factorization.

21323112012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7136342 (or 7136337 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21323112012 its reverse (21021132312), we get a palindrome (42344244324).

The spelling of 21323112012 in words is "twenty-one billion, three hundred twenty-three million, one hundred twelve thousand, twelve".