21449020320 has 720 divisors, whose sum is σ = 93744604800. Its totient is φ = 4522272768.

The previous prime is 21449020289. The next prime is 21449020331. The reversal of 21449020320 is 2302094412.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 15330981 + ... + 15332379.

It is an arithmetic number, because the mean of its divisors is an integer number (130200840).

Almost surely, 2^21449020320 is an apocalyptic number.

21449020320 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 21449020320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46872302400).

21449020320 is an abundant number, since it is smaller than the sum of its proper divisors (72295584480).

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

21449020320 is a wasteful number, since it uses less digits than its factorization.

21449020320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1459 (or 1429 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The spelling of 21449020320 in words is "twenty-one billion, four hundred forty-nine million, twenty thousand, three hundred twenty".