8221993 has 16 divisors (see below), whose sum is σ = 9288720. Its totient is φ = 7225344.

The previous prime is 8221991. The next prime is 8222009. The reversal of 8221993 is 3991228.

It can be written as a sum of positive squares in 8 ways, for example, as 2968729 + 5253264 = 1723^2 + 2292^2 .

It is a cyclic number.

It is not a de Polignac number, because 8221993 - 2¹ = 8221991 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8221991) 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, 42505 + ... + 42697.

It is an arithmetic number, because the mean of its divisors is an integer number (580545).

Almost surely, 2^8221993 is an apocalyptic number.

It is an amenable number.

8221993 is a deficient number, since it is larger than the sum of its proper divisors (1066727).

8221993 is a wasteful number, since it uses less digits than its factorization.

8221993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348.

The product of its digits is 7776, while the sum is 34.

The square root of 8221993 is about 2867.4017855892. The cubic root of 8221993 is about 201.8330892558.

The spelling of 8221993 in words is "eight million, two hundred twenty-one thousand, nine hundred ninety-three".