636538 has 16 divisors (see below), whose sum is σ = 1149120. Its totient is φ = 258336.

The previous prime is 636533. The next prime is 636539. The reversal of 636538 is 835636.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (636533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 931 + ... + 1462.

It is an arithmetic number, because the mean of its divisors is an integer number (71820).

2⁶³⁶⁵³⁸ is an apocalyptic number.

636538 is a deficient number, since it is larger than the sum of its proper divisors (512582).

636538 is a wasteful number, since it uses less digits than its factorization.

636538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2421.

The product of its digits is 12960, while the sum is 31.

The square root of 636538 is about 797.8333159251. The cubic root of 636538 is about 86.0217179691.

The spelling of 636538 in words is "six hundred thirty-six thousand, five hundred thirty-eight".