9686640 has 40 divisors (see below), whose sum is σ = 30029328. Its totient is φ = 2583040.

The previous prime is 9686629. The next prime is 9686647. The reversal of 9686640 is 466869.

9686640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9686647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19941 + ... + 20420.

Almost surely, 2^9686640 is an apocalyptic number.

It is an amenable number.

9686640 is an abundant number, since it is smaller than the sum of its proper divisors (20342688).

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

9686640 is a wasteful number, since it uses less digits than its factorization.

9686640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40377 (or 40371 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 9686640 is about 3112.3367427064. The cubic root of 9686640 is about 213.1691662351.

Subtracting from 9686640 its sum of digits (39), we obtain a triangular number (9686601 = T₄₄₀₁).

It can be divided in two parts, 96 and 86640, that added together give a triangular number (86736 = T₄₁₆).

The spelling of 9686640 in words is "nine million, six hundred eighty-six thousand, six hundred forty".