8221215 has 16 divisors (see below), whose sum is σ = 13510368. Its totient is φ = 4265856.

The previous prime is 8221211. The next prime is 8221219. The reversal of 8221215 is 5121228.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (8221211) and next prime (8221219).

It is not a de Polignac number, because 8221215 - 2² = 8221211 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8221191 and 8221200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8221211) 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, 6852 + ... + 7961.

It is an arithmetic number, because the mean of its divisors is an integer number (844398).

Almost surely, 2^8221215 is an apocalyptic number.

8221215 is a deficient number, since it is larger than the sum of its proper divisors (5289153).

8221215 is a wasteful number, since it uses less digits than its factorization.

8221215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14858.

The product of its digits is 320, while the sum is 21.

The square root of 8221215 is about 2867.2661194943. The cubic root of 8221215 is about 201.8267229527.

The spelling of 8221215 in words is "eight million, two hundred twenty-one thousand, two hundred fifteen".