635638 has 8 divisors (see below), whose sum is σ = 964440. Its totient is φ = 314160.

The previous prime is 635617. The next prime is 635639. The reversal of 635638 is 836536.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (635639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1608 + ... + 1963.

It is an arithmetic number, because the mean of its divisors is an integer number (120555).

2⁶³⁵⁶³⁸ is an apocalyptic number.

635638 is a deficient number, since it is larger than the sum of its proper divisors (328802).

635638 is a wasteful number, since it uses less digits than its factorization.

635638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3662.

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

The square root of 635638 is about 797.2690888276. The cubic root of 635638 is about 85.9811568596.

The spelling of 635638 in words is "six hundred thirty-five thousand, six hundred thirty-eight".