861584 has 10 divisors (see below), whose sum is σ = 1669350. Its totient is φ = 430784.

The previous prime is 861571. The next prime is 861589. The reversal of 861584 is 485168.

It can be written as a sum of positive squares in only one way, i.e., 861184 + 400 = 928^2 + 20^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 861584.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 861584.

It is not an unprimeable number, because it can be changed into a prime (861589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26909 + ... + 26940.

It is an arithmetic number, because the mean of its divisors is an integer number (166935).

2⁸⁶¹⁵⁸⁴ is an apocalyptic number.

It is an amenable number.

861584 is a deficient number, since it is larger than the sum of its proper divisors (807766).

861584 is a wasteful number, since it uses less digits than its factorization.

861584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53857 (or 53851 counting only the distinct ones).

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

The square root of 861584 is about 928.2154922215. The cubic root of 861584 is about 95.1552033668.

The spelling of 861584 in words is "eight hundred sixty-one thousand, five hundred eighty-four".