861943 has 4 divisors (see below), whose sum is σ = 883008. Its totient is φ = 840880.

The previous prime is 861941. The next prime is 861947. The reversal of 861943 is 349168.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 861943 - 2¹ = 861941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861941) 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, 10471 + ... + 10552.

It is an arithmetic number, because the mean of its divisors is an integer number (220752).

2⁸⁶¹⁹⁴³ is an apocalyptic number.

861943 is a deficient number, since it is larger than the sum of its proper divisors (21065).

861943 is a wasteful number, since it uses less digits than its factorization.

861943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21064.

The product of its digits is 5184, while the sum is 31.

The square root of 861943 is about 928.4088539000. The cubic root of 861943 is about 95.1684177775.

The spelling of 861943 in words is "eight hundred sixty-one thousand, nine hundred forty-three".