21021011320 has 64 divisors (see below), whose sum is σ = 48436807680. Its totient is φ = 8206809216.

The previous prime is 21021011281. The next prime is 21021011339. The reversal of 21021011320 is 2311012012.

It is a self number, because there is not a number n which added to its sum of digits gives 21021011320.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 674727 + ... + 705193.

It is an arithmetic number, because the mean of its divisors is an integer number (756825120).

Almost surely, 2^21021011320 is an apocalyptic number.

21021011320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21021011320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24218403840).

21021011320 is an abundant number, since it is smaller than the sum of its proper divisors (27415796360).

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

21021011320 is a wasteful number, since it uses less digits than its factorization.

21021011320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30892 (or 30888 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21021011320 its reverse (2311012012), we get a palindrome (23332023332).

The spelling of 21021011320 in words is "twenty-one billion, twenty-one million, eleven thousand, three hundred twenty".