8543981 has 4 divisors (see below), whose sum is σ = 8552892. Its totient is φ = 8535072.

The previous prime is 8543963. The next prime is 8543987. The reversal of 8543981 is 1893458.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 3960100 + 4583881 = 1990^2 + 2141^2 .

It is a cyclic number.

It is not a de Polignac number, because 8543981 - 2¹⁸ = 8281837 is a prime.

It is a super-2 number, since 2×8543981² = 145999222656722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8543987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2816 + ... + 5001.

It is an arithmetic number, because the mean of its divisors is an integer number (2138223).

Almost surely, 2^8543981 is an apocalyptic number.

It is an amenable number.

8543981 is a deficient number, since it is larger than the sum of its proper divisors (8911).

8543981 is a wasteful number, since it uses less digits than its factorization.

8543981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8910.

The product of its digits is 34560, while the sum is 38.

The square root of 8543981 is about 2923.0088949574. The cubic root of 8543981 is about 204.4341404722.

The spelling of 8543981 in words is "eight million, five hundred forty-three thousand, nine hundred eighty-one".