8217220 has 48 divisors (see below), whose sum is σ = 19305216. Its totient is φ = 2912000.

The previous prime is 8217203. The next prime is 8217221. The reversal of 8217220 is 227128.

8217220 = T₂₃₁ + T₂₃₂ + ... + T₃₉₄.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 8217191 and 8217200.

It is not an unprimeable number, because it can be changed into a prime (8217221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8565 + ... + 9475.

It is an arithmetic number, because the mean of its divisors is an integer number (402192).

Almost surely, 2^8217220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8217220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9652608).

8217220 is an abundant number, since it is smaller than the sum of its proper divisors (11087996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8217220 is a wasteful number, since it uses less digits than its factorization.

8217220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 8217220 is about 2866.5693781941. The cubic root of 8217220 is about 201.7940259042.

It can be divided in two parts, 82 and 17220, that multiplied together give a triangular number (1412040 = T₁₆₈₀).

The spelling of 8217220 in words is "eight million, two hundred seventeen thousand, two hundred twenty".