8281556640 has 864 divisors, whose sum is σ = 35711020800. Its totient is φ = 1810626048.

The previous prime is 8281556639. The next prime is 8281556669. The reversal of 8281556640 is 466551828.

8281556640 is a `hidden beast` number, since 8 + 2 + 81 + 5 + 566 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 360067669 + ... + 360067691.

It is an arithmetic number, because the mean of its divisors is an integer number (41332200).

Almost surely, 2^8281556640 is an apocalyptic number.

8281556640 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 8281556640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17855510400).

8281556640 is an abundant number, since it is smaller than the sum of its proper divisors (27429464160).

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

8281556640 is an frugal number, since it uses more digits than its factorization.

8281556640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83 (or 40 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 45.

The square root of 8281556640 is about 91003.0584101436. The cubic root of 8281556640 is about 2023.1930547754.

The spelling of 8281556640 in words is "eight billion, two hundred eighty-one million, five hundred fifty-six thousand, six hundred forty".