636140 has 24 divisors (see below), whose sum is σ = 1415232. Its totient is φ = 239360.

The previous prime is 636137. The next prime is 636149. The reversal of 636140 is 41636.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (636149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 596 + ... + 1275.

It is an arithmetic number, because the mean of its divisors is an integer number (58968).

2⁶³⁶¹⁴⁰ is an apocalyptic number.

It is an amenable number.

636140 is an abundant number, since it is smaller than the sum of its proper divisors (779092).

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

636140 is a wasteful number, since it uses less digits than its factorization.

636140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1897 (or 1895 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 636140 is about 797.5838513912. The cubic root of 636140 is about 86.0037856635.

Adding to 636140 its reverse (41636), we get a palindrome (677776).

The spelling of 636140 in words is "six hundred thirty-six thousand, one hundred forty".