2821720320 has 144 divisors (see below), whose sum is σ = 10013310720. Its totient is φ = 752449536.

The previous prime is 2821720289. The next prime is 2821720331. The reversal of 2821720320 is 230271282.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6264 + ... + 75383.

It is an arithmetic number, because the mean of its divisors is an integer number (69536880).

Almost surely, 2^2821720320 is an apocalyptic number.

2821720320 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 2821720320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5006655360).

2821720320 is an abundant number, since it is smaller than the sum of its proper divisors (7191590400).

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

2821720320 is an equidigital number, since it uses as much as digits as its factorization.

2821720320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81677 (or 81657 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 2821720320 is about 53119.8674697142. The cubic root of 2821720320 is about 1413.0948769015.

The spelling of 2821720320 in words is "two billion, eight hundred twenty-one million, seven hundred twenty thousand, three hundred twenty".