861845 has 8 divisors (see below), whose sum is σ = 1045464. Its totient is φ = 681984.

The previous prime is 861829. The next prime is 861853. The reversal of 861845 is 548168.

861845 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 75076 + 786769 = 274^2 + 887^2 .

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 861845 - 2⁴ = 861829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 404 + ... + 1373.

It is an arithmetic number, because the mean of its divisors is an integer number (130683).

2⁸⁶¹⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

861845 is a deficient number, since it is larger than the sum of its proper divisors (183619).

861845 is a wasteful number, since it uses less digits than its factorization.

861845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1879.

The product of its digits is 7680, while the sum is 32.

The square root of 861845 is about 928.3560739285. The cubic root of 861845 is about 95.1648108652.

The spelling of 861845 in words is "eight hundred sixty-one thousand, eight hundred forty-five".