21021333312 has 112 divisors (see below), whose sum is σ = 63807270912. Its totient is φ = 5983157760.

The previous prime is 21021333301. The next prime is 21021333349. The reversal of 21021333312 is 21333312012.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 323737 + ... + 383207.

It is an arithmetic number, because the mean of its divisors is an integer number (569707776).

Almost surely, 2^21021333312 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 21021333312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31903635456).

21021333312 is an abundant number, since it is smaller than the sum of its proper divisors (42785937600).

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

21021333312 is a wasteful number, since it uses less digits than its factorization.

21021333312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59756 (or 59746 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21021333312 its reverse (21333312012), we get a palindrome (42354645324).

The spelling of 21021333312 in words is "twenty-one billion, twenty-one million, three hundred thirty-three thousand, three hundred twelve".