638042 has 16 divisors (see below), whose sum is σ = 1016064. Its totient is φ = 300000.

The previous prime is 638023. The next prime is 638047. The reversal of 638042 is 240836.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 637999 and 638017.

It is not an unprimeable number, because it can be changed into a prime (638047) 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 7 ways as a sum of consecutive naturals, for example, 2417 + ... + 2667.

It is an arithmetic number, because the mean of its divisors is an integer number (63504).

2⁶³⁸⁰⁴² is an apocalyptic number.

638042 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

638042 is a deficient number, since it is larger than the sum of its proper divisors (378022).

638042 is a wasteful number, since it uses less digits than its factorization.

638042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 638042 is about 798.7753125880. The cubic root of 638042 is about 86.0894148446.

Adding to 638042 its reverse (240836), we get a palindrome (878878).

The spelling of 638042 in words is "six hundred thirty-eight thousand, forty-two".