8166321 has 6 divisors (see below), whose sum is σ = 11795810. Its totient is φ = 5444208.

The previous prime is 8166317. The next prime is 8166331. The reversal of 8166321 is 1236618.

It can be written as a sum of positive squares in only one way, i.e., 7485696 + 680625 = 2736^2 + 825^2 .

It is not a de Polignac number, because 8166321 - 2² = 8166317 is a prime.

It is a Duffinian number.

It is a Curzon number.

8166321 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8166331) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 453676 + ... + 453693.

Almost surely, 2^8166321 is an apocalyptic number.

It is an amenable number.

8166321 is a deficient number, since it is larger than the sum of its proper divisors (3629489).

8166321 is a wasteful number, since it uses less digits than its factorization.

8166321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907375 (or 907372 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 8166321 is about 2857.6775535389. The cubic root of 8166321 is about 201.3765126628.

The spelling of 8166321 in words is "eight million, one hundred sixty-six thousand, three hundred twenty-one".