8921129280 has 448 divisors, whose sum is σ = 34445813760. Its totient is φ = 1910808576.

The previous prime is 8921129257. The next prime is 8921129291. The reversal of 8921129280 is 829211298.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13661434 + ... + 13662086.

Almost surely, 2^8921129280 is an apocalyptic number.

8921129280 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 8921129280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17222906880).

8921129280 is an abundant number, since it is smaller than the sum of its proper divisors (25524684480).

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

8921129280 is a wasteful number, since it uses less digits than its factorization.

8921129280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806 (or 796 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 42.

The square root of 8921129280 is about 94451.7298941634. The cubic root of 8921129280 is about 2073.9897752422.

The spelling of 8921129280 in words is "eight billion, nine hundred twenty-one million, one hundred twenty-nine thousand, two hundred eighty".