638118 has 48 divisors (see below), whose sum is σ = 1559376. Its totient is φ = 194400.

The previous prime is 638117. The next prime is 638123. The reversal of 638118 is 811836.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 638091 and 638100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6268 + ... + 6368.

It is an arithmetic number, because the mean of its divisors is an integer number (32487).

2⁶³⁸¹¹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638118, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (779688).

638118 is an abundant number, since it is smaller than the sum of its proper divisors (921258).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638118 is a wasteful number, since it uses less digits than its factorization.

638118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 119 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 638118 is about 798.8228839987. The cubic root of 638118 is about 86.0928328723.

The spelling of 638118 in words is "six hundred thirty-eight thousand, one hundred eighteen".