8686640 has 40 divisors (see below), whose sum is σ = 21079008. Its totient is φ = 3322880.

The previous prime is 8686589. The next prime is 8686651. The reversal of 8686640 is 466868.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 8686594 and 8686603.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521 + ... + 4200.

Almost surely, 2^8686640 is an apocalyptic number.

8686640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8686640 is an abundant number, since it is smaller than the sum of its proper divisors (12392368).

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

8686640 is a wasteful number, since it uses less digits than its factorization.

8686640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4757 (or 4751 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 8686640 is about 2947.3106385313. The cubic root of 8686640 is about 205.5656793434.

The spelling of 8686640 in words is "eight million, six hundred eighty-six thousand, six hundred forty".