638523 has 10 divisors (see below), whose sum is σ = 953964. Its totient is φ = 425628.

The previous prime is 638501. The next prime is 638527. The reversal of 638523 is 325836.

638523 is a `hidden beast` number, since 638 + 5 + 23 = 666.

It is not a de Polignac number, because 638523 - 2⁶ = 638459 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

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

It is a plaindrome in base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638523.

It is not an unprimeable number, because it can be changed into a prime (638527) 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 9 ways as a sum of consecutive naturals, for example, 3861 + ... + 4022.

2⁶³⁸⁵²³ is an apocalyptic number.

638523 is a deficient number, since it is larger than the sum of its proper divisors (315441).

638523 is an equidigital number, since it uses as much as digits as its factorization.

638523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7895 (or 7886 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 638523 is about 799.0763417847. The cubic root of 638523 is about 86.1110427872. Note that the first 3 decimals are identical.

The spelling of 638523 in words is "six hundred thirty-eight thousand, five hundred twenty-three".