8491278240 has 144 divisors (see below), whose sum is σ = 29373788808. Its totient is φ = 2233294848.

The previous prime is 8491278217. The next prime is 8491278283. The reversal of 8491278240 is 428721948.

It can be written as a sum of positive squares in 4 ways, for example, as 8442669456 + 48608784 = 91884^2 + 6972^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×8491278240² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64732 + ... + 145508.

Almost surely, 2^8491278240 is an apocalyptic number.

8491278240 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 8491278240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14686894404).

8491278240 is an abundant number, since it is smaller than the sum of its proper divisors (20882510568).

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

8491278240 is a wasteful number, since it uses less digits than its factorization.

8491278240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80871 (or 80860 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 8491278240 is about 92148.1320483492. The cubic root of 8491278240 is about 2040.1292882304.

The spelling of 8491278240 in words is "eight billion, four hundred ninety-one million, two hundred seventy-eight thousand, two hundred forty".