8185821 has 16 divisors (see below), whose sum is σ = 12593664. Its totient is φ = 4632624.

The previous prime is 8185819. The next prime is 8185873. The reversal of 8185821 is 1285818.

It is not a de Polignac number, because 8185821 - 2¹ = 8185819 is a prime.

It is an Ulam number.

It is a Curzon number.

8185821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8185421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 426 + ... + 4068.

It is an arithmetic number, because the mean of its divisors is an integer number (787104).

Almost surely, 2^8185821 is an apocalyptic number.

It is an amenable number.

8185821 is a deficient number, since it is larger than the sum of its proper divisors (4407843).

8185821 is a wasteful number, since it uses less digits than its factorization.

8185821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3760.

The product of its digits is 5120, while the sum is 33.

The square root of 8185821 is about 2861.0873806999. The cubic root of 8185821 is about 201.5366713013.

The spelling of 8185821 in words is "eight million, one hundred eighty-five thousand, eight hundred twenty-one".