8921779680 has 384 divisors, whose sum is σ = 31579269120. Its totient is φ = 2099036160.

The previous prime is 8921779651. The next prime is 8921779681. The reversal of 8921779680 is 869771298.

It is a self number, because there is not a number n which added to its sum of digits gives 8921779680.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8921779681) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30449614 + ... + 30449906.

It is an arithmetic number, because the mean of its divisors is an integer number (82237680).

Almost surely, 2^8921779680 is an apocalyptic number.

8921779680 is a gapful number since it is divisible by the number (80) 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 8921779680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15789634560).

8921779680 is an abundant number, since it is smaller than the sum of its proper divisors (22657489440).

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

8921779680 is a wasteful number, since it uses less digits than its factorization.

8921779680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474 (or 466 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 57.

The square root of 8921779680 is about 94455.1728599339. The cubic root of 8921779680 is about 2074.0401758185.

The spelling of 8921779680 in words is "eight billion, nine hundred twenty-one million, seven hundred seventy-nine thousand, six hundred eighty".