843981 has 4 divisors (see below), whose sum is σ = 1125312. Its totient is φ = 562652.

The previous prime is 843911. The next prime is 844001. The reversal of 843981 is 189348.

843981 is digitally balanced in base 2, 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 843981 - 2¹⁰ = 842957 is a prime.

It is a super-2 number, since 2×843981² = 1424607856722, which contains 22 as substring.

It is a D-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 (843901) 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, 140661 + ... + 140666.

It is an arithmetic number, because the mean of its divisors is an integer number (281328).

2⁸⁴³⁹⁸¹ is an apocalyptic number.

It is an amenable number.

843981 is a deficient number, since it is larger than the sum of its proper divisors (281331).

843981 is a wasteful number, since it uses less digits than its factorization.

843981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281330.

The product of its digits is 6912, while the sum is 33.

The square root of 843981 is about 918.6843854121. The cubic root of 843981 is about 94.5027014149.

The spelling of 843981 in words is "eight hundred forty-three thousand, nine hundred eighty-one".