8239981 has 4 divisors (see below), whose sum is σ = 8246592. Its totient is φ = 8233372.

The previous prime is 8239969. The next prime is 8239997. The reversal of 8239981 is 1899328.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8239981 is a prime.

It is a super-2 number, since 2×8239981² = 135794573760722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8239921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 805 + ... + 4138.

It is an arithmetic number, because the mean of its divisors is an integer number (2061648).

Almost surely, 2^8239981 is an apocalyptic number.

It is an amenable number.

8239981 is a deficient number, since it is larger than the sum of its proper divisors (6611).

8239981 is a wasteful number, since it uses less digits than its factorization.

8239981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6610.

The product of its digits is 31104, while the sum is 40.

The square root of 8239981 is about 2870.5367093977. The cubic root of 8239981 is about 201.9801715661.

The spelling of 8239981 in words is "eight million, two hundred thirty-nine thousand, nine hundred eighty-one".