8720321280 has 144 divisors (see below), whose sum is σ = 30382539264. Its totient is φ = 2114007040.

The previous prime is 8720321273. The next prime is 8720321321. The reversal of 8720321280 is 821230278.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 60984 + ... + 145463.

It is an arithmetic number, because the mean of its divisors is an integer number (210989856).

Almost surely, 2^8720321280 is an apocalyptic number.

8720321280 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8720321280 is an abundant number, since it is smaller than the sum of its proper divisors (21662217984).

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

8720321280 is a wasteful number, since it uses less digits than its factorization.

8720321280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206482 (or 206468 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 8720321280 is about 93382.6604889794. The cubic root of 8720321280 is about 2058.3102113411.

The spelling of 8720321280 in words is "eight billion, seven hundred twenty million, three hundred twenty-one thousand, two hundred eighty".