8638981 has 4 divisors (see below), whose sum is σ = 9303532. Its totient is φ = 7974432.

The previous prime is 8638967. The next prime is 8638991. The reversal of 8638981 is 1898368.

It is a happy number.

8638981 is digitally balanced in base 3, 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 1664100 + 6974881 = 1290^2 + 2641^2 .

It is a cyclic number.

It is not a de Polignac number, because 8638981 - 2⁷ = 8638853 is a prime.

It is a super-2 number, since 2×8638981² = 149263985436722, which contains 22 as substring.

It is a Duffinian number.

8638981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8638951) 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, 332256 + ... + 332281.

It is an arithmetic number, because the mean of its divisors is an integer number (2325883).

Almost surely, 2^8638981 is an apocalyptic number.

It is an amenable number.

8638981 is a deficient number, since it is larger than the sum of its proper divisors (664551).

8638981 is a wasteful number, since it uses less digits than its factorization.

8638981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664550.

The product of its digits is 82944, while the sum is 43.

The square root of 8638981 is about 2939.2143508087. The cubic root of 8638981 is about 205.1890463142.

The spelling of 8638981 in words is "eight million, six hundred thirty-eight thousand, nine hundred eighty-one".