8218709 has 4 divisors (see below), whose sum is σ = 8294220. Its totient is φ = 8143200.

The previous prime is 8218703. The next prime is 8218723. The reversal of 8218709 is 9078128.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4318084 + 3900625 = 2078^2 + 1975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8218709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8218703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37592 + ... + 37809.

It is an arithmetic number, because the mean of its divisors is an integer number (2073555).

Almost surely, 2^8218709 is an apocalyptic number.

It is an amenable number.

8218709 is a deficient number, since it is larger than the sum of its proper divisors (75511).

8218709 is a wasteful number, since it uses less digits than its factorization.

8218709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75510.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 8218709 is about 2866.8290845462. The cubic root of 8218709 is about 201.8062138525.

The spelling of 8218709 in words is "eight million, two hundred eighteen thousand, seven hundred nine".