861636 has 24 divisors (see below), whose sum is σ = 2046240. Its totient is φ = 282112.

The previous prime is 861617. The next prime is 861647. The reversal of 861636 is 636168.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

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, 100 + ... + 1316.

It is an arithmetic number, because the mean of its divisors is an integer number (85260).

2⁸⁶¹⁶³⁶ is an apocalyptic number.

It is an amenable number.

861636 is an abundant number, since it is smaller than the sum of its proper divisors (1184604).

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

861636 is a wasteful number, since it uses less digits than its factorization.

861636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1283 (or 1281 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 861636 is about 928.2435025358. The cubic root of 861636 is about 95.1571176592.

The spelling of 861636 in words is "eight hundred sixty-one thousand, six hundred thirty-six".