636984 has 40 divisors (see below), whose sum is σ = 1785960. Its totient is φ = 212112.

The previous prime is 636983. The next prime is 636997. The reversal of 636984 is 489636.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 636984.

It is not an unprimeable number, because it can be changed into a prime (636983) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 157 + ... + 1139.

It is an arithmetic number, because the mean of its divisors is an integer number (44649).

2⁶³⁶⁹⁸⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 636984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (892980).

636984 is an abundant number, since it is smaller than the sum of its proper divisors (1148976).

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

636984 is a wasteful number, since it uses less digits than its factorization.

636984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001 (or 988 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 636984 is about 798.1127739862. The cubic root of 636984 is about 86.0418040856.

The spelling of 636984 in words is "six hundred thirty-six thousand, nine hundred eighty-four".