8643840 has 72 divisors (see below), whose sum is σ = 27618528. Its totient is φ = 2304000.

The previous prime is 8643839. The next prime is 8643851. The reversal of 8643840 is 483468.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2715 + ... + 4965.

Almost surely, 2^8643840 is an apocalyptic number.

8643840 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 8643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13809264).

8643840 is an abundant number, since it is smaller than the sum of its proper divisors (18974688).

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

8643840 is a wasteful number, since it uses less digits than its factorization.

8643840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2275 (or 2261 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 33.

The square root of 8643840 is about 2940.0408160432. The cubic root of 8643840 is about 205.2275086711.

The spelling of 8643840 in words is "eight million, six hundred forty-three thousand, eight hundred forty".