638543 has 4 divisors (see below), whose sum is σ = 642408. Its totient is φ = 634680.

The previous prime is 638527. The next prime is 638567. The reversal of 638543 is 345836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638543 - 2⁴ = 638527 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (637543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1673 + ... + 2018.

It is an arithmetic number, because the mean of its divisors is an integer number (160602).

2⁶³⁸⁵⁴³ is an apocalyptic number.

638543 is a deficient number, since it is larger than the sum of its proper divisors (3865).

638543 is a wasteful number, since it uses less digits than its factorization.

638543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3864.

The product of its digits is 8640, while the sum is 29.

The square root of 638543 is about 799.0888561355. The cubic root of 638543 is about 86.1119418427. Note that the first 3 decimals are identical.

The spelling of 638543 in words is "six hundred thirty-eight thousand, five hundred forty-three".