8221918 has 16 divisors (see below), whose sum is σ = 12774384. Its totient is φ = 3965760.

The previous prime is 8221903. The next prime is 8221919. The reversal of 8221918 is 8191228.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 8221918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8221919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9733 + ... + 10543.

It is an arithmetic number, because the mean of its divisors is an integer number (798399).

Almost surely, 2^8221918 is an apocalyptic number.

8221918 is a deficient number, since it is larger than the sum of its proper divisors (4552466).

8221918 is a wasteful number, since it uses less digits than its factorization.

8221918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987.

The product of its digits is 2304, while the sum is 31.

The square root of 8221918 is about 2867.3887075177. The cubic root of 8221918 is about 201.8324755551.

The spelling of 8221918 in words is "eight million, two hundred twenty-one thousand, nine hundred eighteen".