5638 has 4 divisors (see below), whose sum is σ = 8460.
Its totient is φ = 2818.
The previous prime is 5623. The next prime is 5639. The reversal of 5638 is 8365.
5638 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.
It is a semiprime because it is the product of two primes.
It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.
It is an alternating number because its digits alternate between odd and even.
It is a nialpdrome in base 9.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (5639) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (5) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1408 + ... + 1411.
It is an arithmetic number, because the mean of its divisors is an integer number (2115).
5638 is a deficient number, since it is larger than the sum of its proper divisors (2822).
5638 is a wasteful number, since it uses less digits than its factorization.
5638 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2821.
The product of its digits is 720, while the sum is 22.
The square root of 5638 is about 75.0866166504.
The cubic root of 5638 is about 17.7981566075.
The spelling of 5638 in words is "five thousand, six hundred thirty-eight".