8666640 has 60 divisors (see below), whose sum is σ = 29107884. Its totient is φ = 2310912.

The previous prime is 8666627. The next prime is 8666681. The reversal of 8666640 is 466668.

It can be written as a sum of positive squares in 2 ways, for example, as 1115136 + 7551504 = 1056^2 + 2748^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×8666640² = 150221297779200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 8666595 and 8666604.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5299 + ... + 6738.

Almost surely, 2^8666640 is an apocalyptic number.

8666640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8666640 is an abundant number, since it is smaller than the sum of its proper divisors (20441244).

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

8666640 is a wasteful number, since it uses less digits than its factorization.

8666640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12056 (or 12047 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 8666640 is about 2943.9157596643. The cubic root of 8666640 is about 205.4077942499.

The spelling of 8666640 in words is "eight million, six hundred sixty-six thousand, six hundred forty".