8540640 has 120 divisors (see below), whose sum is σ = 30187080. Its totient is φ = 2274048.

The previous prime is 8540639. The next prime is 8540683. The reversal of 8540640 is 460458.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12631 + ... + 13289.

It is an arithmetic number, because the mean of its divisors is an integer number (251559).

Almost surely, 2^8540640 is an apocalyptic number.

8540640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8540640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15093540).

8540640 is an abundant number, since it is smaller than the sum of its proper divisors (21646440).

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

8540640 is a wasteful number, since it uses less digits than its factorization.

8540640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 8540640 is about 2922.4373389347. The cubic root of 8540640 is about 204.4074899951.

It can be divided in two parts, 8540 and 640, that added together give a triangular number (9180 = T₁₃₅).

The spelling of 8540640 in words is "eight million, five hundred forty thousand, six hundred forty".