8663640 has 128 divisors (see below), whose sum is σ = 28131840. Its totient is φ = 2128896.

The previous prime is 8663621. The next prime is 8663653. The reversal of 8663640 is 463668.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 118644 + ... + 118716.

It is an arithmetic number, because the mean of its divisors is an integer number (219780).

Almost surely, 2^8663640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8663640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14065920).

8663640 is an abundant number, since it is smaller than the sum of its proper divisors (19468200).

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

8663640 is a wasteful number, since it uses less digits than its factorization.

8663640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 8663640 is about 2943.4061901138. The cubic root of 8663640 is about 205.3840905424.

The spelling of 8663640 in words is "eight million, six hundred sixty-three thousand, six hundred forty".