8640861 has 8 divisors (see below), whose sum is σ = 11538240. Its totient is φ = 5752032.

The previous prime is 8640859. The next prime is 8640871. The reversal of 8640861 is 1680468.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 8640861 - 2¹ = 8640859 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8640871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 801 + ... + 4233.

It is an arithmetic number, because the mean of its divisors is an integer number (1442280).

Almost surely, 2^8640861 is an apocalyptic number.

It is an amenable number.

8640861 is a deficient number, since it is larger than the sum of its proper divisors (2897379).

8640861 is a wasteful number, since it uses less digits than its factorization.

8640861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4275.

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 8640861 is about 2939.5341467654. The cubic root of 8640861 is about 205.2039295289.

The spelling of 8640861 in words is "eight million, six hundred forty thousand, eight hundred sixty-one".