8621 has 4 divisors (see below), whose sum is σ = 8892. Its totient is φ = 8352.

The previous prime is 8609. The next prime is 8623. The reversal of 8621 is 1268.

8621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4900 + 3721 = 70^2 + 61^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8621 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 8621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80 + ... + 153.

It is an arithmetic number, because the mean of its divisors is an integer number (2223).

2⁸⁶²¹ is an apocalyptic number.

It is an amenable number.

8621 is a deficient number, since it is larger than the sum of its proper divisors (271).

8621 is a wasteful number, since it uses less digits than its factorization.

8621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270.

The product of its digits is 96, while the sum is 17.

The square root of 8621 is about 92.8493403315. The cubic root of 8621 is about 20.5046588658.

Adding to 8621 its reverse (1268), we get a palindrome (9889).

The spelling of 8621 in words is "eight thousand, six hundred twenty-one".