8780721408 has 648 divisors, whose sum is σ = 30614770368. Its totient is φ = 2496282624.

The previous prime is 8780721379. The next prime is 8780721421. The reversal of 8780721408 is 8041270878.

It is a tau number, because it is divible by the number of its divisors (648).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 381770485 + ... + 381770507.

It is an arithmetic number, because the mean of its divisors is an integer number (47245016).

Almost surely, 2^8780721408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8780721408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15307385184).

8780721408 is an abundant number, since it is smaller than the sum of its proper divisors (21834048960).

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

8780721408 is a wasteful number, since it uses less digits than its factorization.

8780721408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 200704, while the sum is 45.

The square root of 8780721408 is about 93705.5036163832. The cubic root of 8780721408 is about 2063.0514841309.

The spelling of 8780721408 in words is "eight billion, seven hundred eighty million, seven hundred twenty-one thousand, four hundred eight".