8685821 has 4 divisors (see below), whose sum is σ = 8718144. Its totient is φ = 8653500.

The previous prime is 8685791. The next prime is 8685847. The reversal of 8685821 is 1285868.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8685821 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 (8681821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15755 + ... + 16296.

It is an arithmetic number, because the mean of its divisors is an integer number (2179536).

Almost surely, 2^8685821 is an apocalyptic number.

It is an amenable number.

8685821 is a deficient number, since it is larger than the sum of its proper divisors (32323).

8685821 is a wasteful number, since it uses less digits than its factorization.

8685821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32322.

The product of its digits is 30720, while the sum is 38.

The square root of 8685821 is about 2947.1716950324. The cubic root of 8685821 is about 205.5592187103.

The spelling of 8685821 in words is "eight million, six hundred eighty-five thousand, eight hundred twenty-one".