8681621 has 4 divisors (see below), whose sum is σ = 9349452. Its totient is φ = 8013792.

The previous prime is 8681587. The next prime is 8681623. The reversal of 8681621 is 1261868.

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 1999396 + 6682225 = 1414^2 + 2585^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8681621 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 (8681623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 333896 + ... + 333921.

It is an arithmetic number, because the mean of its divisors is an integer number (2337363).

Almost surely, 2^8681621 is an apocalyptic number.

It is an amenable number.

8681621 is a deficient number, since it is larger than the sum of its proper divisors (667831).

8681621 is a wasteful number, since it uses less digits than its factorization.

8681621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667830.

The product of its digits is 4608, while the sum is 32.

The square root of 8681621 is about 2946.4590613141. The cubic root of 8681621 is about 205.5260808751.

The spelling of 8681621 in words is "eight million, six hundred eighty-one thousand, six hundred twenty-one".