8396821 has 4 divisors (see below), whose sum is σ = 8539200. Its totient is φ = 8254444.

The previous prime is 8396819. The next prime is 8396849. The reversal of 8396821 is 1286938.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1286938 = 2 ⋅643469.

It is a cyclic number.

It is not a de Polignac number, because 8396821 - 2¹ = 8396819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8396881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71101 + ... + 71218.

It is an arithmetic number, because the mean of its divisors is an integer number (2134800).

Almost surely, 2^8396821 is an apocalyptic number.

It is an amenable number.

8396821 is a deficient number, since it is larger than the sum of its proper divisors (142379).

8396821 is a wasteful number, since it uses less digits than its factorization.

8396821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142378.

The product of its digits is 20736, while the sum is 37.

The square root of 8396821 is about 2897.7268677362. The cubic root of 8396821 is about 203.2536242859.

The spelling of 8396821 in words is "eight million, three hundred ninety-six thousand, eight hundred twenty-one".