8557640 has 64 divisors (see below), whose sum is σ = 23708160. Its totient is φ = 2707200.

The previous prime is 8557609. The next prime is 8557649. The reversal of 8557640 is 467558.

8557640 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 8557640.

It is not an unprimeable number, because it can be changed into a prime (8557649) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2465 + ... + 4815.

It is an arithmetic number, because the mean of its divisors is an integer number (370440).

Almost surely, 2^8557640 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 8557640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11854080).

8557640 is an abundant number, since it is smaller than the sum of its proper divisors (15150520).

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

8557640 is a wasteful number, since it uses less digits than its factorization.

8557640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2382 (or 2378 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 35.

The square root of 8557640 is about 2925.3444241662. The cubic root of 8557640 is about 204.5430233306.

The spelling of 8557640 in words is "eight million, five hundred fifty-seven thousand, six hundred forty".