8721518 has 32 divisors (see below), whose sum is σ = 14968800. Its totient is φ = 3782016.

The previous prime is 8721511. The next prime is 8721533. The reversal of 8721518 is 8151278.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8721511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32288 + ... + 32556.

It is an arithmetic number, because the mean of its divisors is an integer number (467775).

Almost surely, 2^8721518 is an apocalyptic number.

8721518 is a deficient number, since it is larger than the sum of its proper divisors (6247282).

8721518 is a wasteful number, since it uses less digits than its factorization.

8721518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356.

The product of its digits is 4480, while the sum is 32.

The square root of 8721518 is about 2953.2216306942. The cubic root of 8721518 is about 205.8404363389.

The spelling of 8721518 in words is "eight million, seven hundred twenty-one thousand, five hundred eighteen".