638922 has 8 divisors (see below), whose sum is σ = 1277856. Its totient is φ = 212972.

The previous prime is 638893. The next prime is 638923. The reversal of 638922 is 229836.

638922 is nontrivially palindromic in base 15.

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

638922 is an admirable number.

It is a d-powerful number, because it can be written as 6⁶ + 3¹⁰ + 9³ + 8 + 2¹³ + 2¹⁹ .

It is a self number, because there is not a number n which added to its sum of digits gives 638922.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638922.

It is not an unprimeable number, because it can be changed into a prime (638923) by changing a digit.

638922 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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53238 + ... + 53249.

It is an arithmetic number, because the mean of its divisors is an integer number (159732).

2⁶³⁸⁹²² is an apocalyptic number.

638922 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

638922 is a wasteful number, since it uses less digits than its factorization.

638922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106492.

The product of its digits is 5184, while the sum is 30.

The square root of 638922 is about 799.3259660489. The cubic root of 638922 is about 86.1289753972.

The spelling of 638922 in words is "six hundred thirty-eight thousand, nine hundred twenty-two".