21023213312 has 72 divisors (see below), whose sum is σ = 42310800000. Its totient is φ = 10425203712.

The previous prime is 21023213311. The next prime is 21023213357. The reversal of 21023213312 is 21331232012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023213311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25420643 + ... + 25421469.

It is an arithmetic number, because the mean of its divisors is an integer number (587650000).

Almost surely, 2^21023213312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21023213312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21155400000).

21023213312 is an abundant number, since it is smaller than the sum of its proper divisors (21287586688).

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

21023213312 is an equidigital number, since it uses as much as digits as its factorization.

21023213312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1541 (or 1527 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21023213312 its reverse (21331232012), we get a palindrome (42354445324).

The spelling of 21023213312 in words is "twenty-one billion, twenty-three million, two hundred thirteen thousand, three hundred twelve".