21013272320 has 72 divisors (see below), whose sum is σ = 50367880080. Its totient is φ = 8399544320.

The previous prime is 21013272311. The next prime is 21013272337. The reversal of 21013272320 is 2327231012.

It is a super-2 number, since 2×21013272320² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2198111 + ... + 2207649.

It is an arithmetic number, because the mean of its divisors is an integer number (699553890).

Almost surely, 2^21013272320 is an apocalyptic number.

21013272320 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 21013272320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25183940040).

21013272320 is an abundant number, since it is smaller than the sum of its proper divisors (29354607760).

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

21013272320 is an equidigital number, since it uses as much as digits as its factorization.

21013272320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11281 (or 11267 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 23.

The spelling of 21013272320 in words is "twenty-one billion, thirteen million, two hundred seventy-two thousand, three hundred twenty".