8216815 has 4 divisors (see below), whose sum is σ = 9860184. Its totient is φ = 6573448.

The previous prime is 8216809. The next prime is 8216821. The reversal of 8216815 is 5186128.

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

It is an interprime number because it is at equal distance from previous prime (8216809) and next prime (8216821).

It is a cyclic number.

It is not a de Polignac number, because 8216815 - 2⁵ = 8216783 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821677 + ... + 821686.

It is an arithmetic number, because the mean of its divisors is an integer number (2465046).

Almost surely, 2^8216815 is an apocalyptic number.

8216815 is a deficient number, since it is larger than the sum of its proper divisors (1643369).

8216815 is a wasteful number, since it uses less digits than its factorization.

8216815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643368.

The product of its digits is 3840, while the sum is 31.

The square root of 8216815 is about 2866.4987353913. The cubic root of 8216815 is about 201.7907105931.

The spelling of 8216815 in words is "eight million, two hundred sixteen thousand, eight hundred fifteen".