8521539840 has 216 divisors, whose sum is σ = 32164449408. Its totient is φ = 2065797120.

The previous prime is 8521539839. The next prime is 8521539857. The reversal of 8521539840 is 489351258.

8521539840 is a `hidden beast` number, since 8 + 5 + 215 + 398 + 40 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 93097 + ... + 160343.

It is an arithmetic number, because the mean of its divisors is an integer number (148909488).

Almost surely, 2^8521539840 is an apocalyptic number.

8521539840 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 8521539840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16082224704).

8521539840 is an abundant number, since it is smaller than the sum of its proper divisors (23642909568).

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

8521539840 is a wasteful number, since it uses less digits than its factorization.

8521539840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67285 (or 67268 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The square root of 8521539840 is about 92312.1868444248. The cubic root of 8521539840 is about 2042.5499830712.

The spelling of 8521539840 in words is "eight billion, five hundred twenty-one million, five hundred thirty-nine thousand, eight hundred forty".