8641563840 has 896 divisors, whose sum is σ = 38916864000. Its totient is φ = 1755758592.

The previous prime is 8641563829. The next prime is 8641563859. The reversal of 8641563840 is 483651468.

8641563840 is a `hidden beast` number, since 8 + 6 + 4 + 1 + 5 + 638 + 4 + 0 = 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 127 ways as a sum of consecutive naturals, for example, 22800771 + ... + 22801149.

It is an arithmetic number, because the mean of its divisors is an integer number (43434000).

Almost surely, 2^8641563840 is an apocalyptic number.

8641563840 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 8641563840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19458432000).

8641563840 is an abundant number, since it is smaller than the sum of its proper divisors (30275300160).

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

8641563840 is a wasteful number, since it uses less digits than its factorization.

8641563840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454 (or 438 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The square root of 8641563840 is about 92960.0120481920. The cubic root of 8641563840 is about 2052.0949308019.

It can be divided in two parts, 8641563 and 840, that added together give a triangular number (8642403 = T₄₁₅₇).

The spelling of 8641563840 in words is "eight billion, six hundred forty-one million, five hundred sixty-three thousand, eight hundred forty".