638946 has 48 divisors (see below), whose sum is σ = 1729728. Its totient is φ = 165600.

The previous prime is 638933. The next prime is 638959. The reversal of 638946 is 649836.

It is an interprime number because it is at equal distance from previous prime (638933) and next prime (638959).

It is a self number, because there is not a number n which added to its sum of digits gives 638946.

It is an unprimeable number.

638946 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 23 ways as a sum of consecutive naturals, for example, 1156 + ... + 1616.

It is an arithmetic number, because the mean of its divisors is an integer number (36036).

2⁶³⁸⁹⁴⁶ is an apocalyptic number.

638946 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 638946, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (864864).

638946 is an abundant number, since it is smaller than the sum of its proper divisors (1090782).

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

638946 is a wasteful number, since it uses less digits than its factorization.

638946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487 (or 484 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 638946 is about 799.3409785567. The cubic root of 638946 is about 86.1300538124.

It can be divided in two parts, 63 and 8946, that added together give a palindrome (9009).

The spelling of 638946 in words is "six hundred thirty-eight thousand, nine hundred forty-six".