8686821 has 16 divisors (see below), whose sum is σ = 13608000. Its totient is φ = 4859520.

The previous prime is 8686807. The next prime is 8686829. The reversal of 8686821 is 1286868.

It is not a de Polignac number, because 8686821 - 2⁹ = 8686309 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 8686821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8686829) 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, 9696 + ... + 10553.

It is an arithmetic number, because the mean of its divisors is an integer number (850500).

Almost surely, 2^8686821 is an apocalyptic number.

It is an amenable number.

8686821 is a deficient number, since it is larger than the sum of its proper divisors (4921179).

8686821 is a wasteful number, since it uses less digits than its factorization.

8686821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20276.

The product of its digits is 36864, while the sum is 39.

The square root of 8686821 is about 2947.3413443305. The cubic root of 8686821 is about 205.5671070964.

The spelling of 8686821 in words is "eight million, six hundred eighty-six thousand, eight hundred twenty-one".