639244 has 6 divisors (see below), whose sum is σ = 1118684. Its totient is φ = 319620.

The previous prime is 639211. The next prime is 639253. The reversal of 639244 is 442936.

It is a d-powerful number, because it can be written as 6⁷ + 3⁹ + 2¹¹ + 9⁵ + 4⁷ + 4⁹ .

It is an unprimeable 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 as a sum of consecutive naturals, namely, 79902 + ... + 79909.

2⁶³⁹²⁴⁴ is an apocalyptic number.

It is an amenable number.

639244 is a deficient number, since it is larger than the sum of its proper divisors (479440).

639244 is a wasteful number, since it uses less digits than its factorization.

639244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159815 (or 159813 counting only the distinct ones).

The product of its digits is 5184, while the sum is 28.

The square root of 639244 is about 799.5273603824. The cubic root of 639244 is about 86.1434418853.

The spelling of 639244 in words is "six hundred thirty-nine thousand, two hundred forty-four".