8721345 has 16 divisors (see below), whose sum is σ = 14011200. Its totient is φ = 4632384.

The previous prime is 8721329. The next prime is 8721359. The reversal of 8721345 is 5431278.

8721345 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8721345 - 2⁴ = 8721329 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3106 + ... + 5204.

It is an arithmetic number, because the mean of its divisors is an integer number (875700).

Almost surely, 2^8721345 is an apocalyptic number.

It is an amenable number.

8721345 is a deficient number, since it is larger than the sum of its proper divisors (5289855).

8721345 is a wasteful number, since it uses less digits than its factorization.

8721345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2384.

The product of its digits is 6720, while the sum is 30.

The square root of 8721345 is about 2953.1923405021. The cubic root of 8721345 is about 205.8390753132.

The spelling of 8721345 in words is "eight million, seven hundred twenty-one thousand, three hundred forty-five".