861860 has 12 divisors (see below), whose sum is σ = 1809948. Its totient is φ = 344736.

The previous prime is 861857. The next prime is 861871. The reversal of 861860 is 68168.

It can be written as a sum of positive squares in 2 ways, for example, as 287296 + 574564 = 536^2 + 758^2 .

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 861860.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21527 + ... + 21566.

It is an arithmetic number, because the mean of its divisors is an integer number (150829).

2⁸⁶¹⁸⁶⁰ is an apocalyptic number.

It is an amenable number.

861860 is an abundant number, since it is smaller than the sum of its proper divisors (948088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

861860 is a wasteful number, since it uses less digits than its factorization.

861860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43102 (or 43100 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 861860 is about 928.3641526901. The cubic root of 861860 is about 95.1653629614.

The spelling of 861860 in words is "eight hundred sixty-one thousand, eight hundred sixty".