8721540 has 96 divisors (see below), whose sum is σ = 28062720. Its totient is φ = 2246400.

The previous prime is 8721539. The next prime is 8721541. The reversal of 8721540 is 451278.

8721540 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (8721539) and next prime (8721541).

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

It is not an unprimeable number, because it can be changed into a prime (8721541) 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 31 ways as a sum of consecutive naturals, for example, 16480 + ... + 17000.

It is an arithmetic number, because the mean of its divisors is an integer number (292320).

Almost surely, 2^8721540 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 8721540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14031360).

8721540 is an abundant number, since it is smaller than the sum of its proper divisors (19341180).

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

8721540 is a wasteful number, since it uses less digits than its factorization.

8721540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570 (or 562 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 8721540 is about 2953.2253554377. The cubic root of 8721540 is about 205.8406094160.

It can be divided in two parts, 8721 and 540, that added together give a cube (9261 = 21³).

The spelling of 8721540 in words is "eight million, seven hundred twenty-one thousand, five hundred forty".