861839 has 8 divisors (see below), whose sum is σ = 960768. Its totient is φ = 766360.

The previous prime is 861829. The next prime is 861853. The reversal of 861839 is 938168.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 861839 - 2⁴ = 861823 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 861799 and 861808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317 + ... + 1350.

It is an arithmetic number, because the mean of its divisors is an integer number (120096).

2⁸⁶¹⁸³⁹ is an apocalyptic number.

861839 is a deficient number, since it is larger than the sum of its proper divisors (98929).

861839 is a wasteful number, since it uses less digits than its factorization.

861839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1725.

The product of its digits is 10368, while the sum is 35.

The square root of 861839 is about 928.3528424042. The cubic root of 861839 is about 95.1645900250.

The spelling of 861839 in words is "eight hundred sixty-one thousand, eight hundred thirty-nine".