638942 has 8 divisors (see below), whose sum is σ = 964656. Its totient is φ = 317392.

The previous prime is 638933. The next prime is 638959. The reversal of 638942 is 249836.

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

It is a junction number, because it is equal to n+sod(n) for n = 638899 and 638908.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 623 + ... + 1290.

It is an arithmetic number, because the mean of its divisors is an integer number (120582).

2⁶³⁸⁹⁴² is an apocalyptic number.

638942 is a deficient number, since it is larger than the sum of its proper divisors (325714).

638942 is a wasteful number, since it uses less digits than its factorization.

638942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2082.

The product of its digits is 10368, while the sum is 32.

The square root of 638942 is about 799.3384764917. The cubic root of 638942 is about 86.1298740784.

The spelling of 638942 in words is "six hundred thirty-eight thousand, nine hundred forty-two".