636544 has 16 divisors (see below), whose sum is σ = 1268370. Its totient is φ = 318208.

The previous prime is 636541. The next prime is 636547. The reversal of 636544 is 445636.

It is an interprime number because it is at equal distance from previous prime (636541) and next prime (636547).

It can be written as a sum of positive squares in only one way, i.e., 506944 + 129600 = 712^2 + 360^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is not an unprimeable number, because it can be changed into a prime (636541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2359 + ... + 2614.

2⁶³⁶⁵⁴⁴ is an apocalyptic number.

636544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

636544 is a deficient number, since it is larger than the sum of its proper divisors (631826).

636544 is an equidigital number, since it uses as much as digits as its factorization.

636544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4987 (or 4975 counting only the distinct ones).

The product of its digits is 8640, while the sum is 28.

The square root of 636544 is about 797.8370761001. The cubic root of 636544 is about 86.0219882482.

The spelling of 636544 in words is "six hundred thirty-six thousand, five hundred forty-four".