639238 has 8 divisors (see below), whose sum is σ = 981288. Its totient is φ = 312144.

The previous prime is 639211. The next prime is 639253. The reversal of 639238 is 832936.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

639238 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3631 + ... + 3802.

It is an arithmetic number, because the mean of its divisors is an integer number (122661).

2⁶³⁹²³⁸ is an apocalyptic number.

639238 is a deficient number, since it is larger than the sum of its proper divisors (342050).

639238 is a wasteful number, since it uses less digits than its factorization.

639238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7478.

The product of its digits is 7776, while the sum is 31.

The square root of 639238 is about 799.5236081568. The cubic root of 639238 is about 86.1431723678.

The spelling of 639238 in words is "six hundred thirty-nine thousand, two hundred thirty-eight".