8217681 has 16 divisors (see below), whose sum is σ = 11664000. Its totient is φ = 5128448.

The previous prime is 8217679. The next prime is 8217689. The reversal of 8217681 is 1867128.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 8217681 - 2¹ = 8217679 is a prime.

It is a super-2 number, since 2×8217681² = 135060562035522, which contains 22 as substring.

8217681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8217689) 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, 13420 + ... + 14018.

It is an arithmetic number, because the mean of its divisors is an integer number (729000).

Almost surely, 2^8217681 is an apocalyptic number.

It is an amenable number.

8217681 is a deficient number, since it is larger than the sum of its proper divisors (3446319).

8217681 is a wasteful number, since it uses less digits than its factorization.

8217681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888.

The product of its digits is 5376, while the sum is 33.

The square root of 8217681 is about 2866.6497867720. The cubic root of 8217681 is about 201.7977994962.

The spelling of 8217681 in words is "eight million, two hundred seventeen thousand, six hundred eighty-one".