639223 has 4 divisors (see below), whose sum is σ = 688408. Its totient is φ = 590040.

The previous prime is 639211. The next prime is 639253. The reversal of 639223 is 322936.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639223 is a prime.

It is a d-powerful number, because it can be written as 6⁶ + 3³ + 2 + 9⁵ + 2¹¹ + 3¹² .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24573 + ... + 24598.

It is an arithmetic number, because the mean of its divisors is an integer number (172102).

2⁶³⁹²²³ is an apocalyptic number.

639223 is a deficient number, since it is larger than the sum of its proper divisors (49185).

639223 is a wasteful number, since it uses less digits than its factorization.

639223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49184.

The product of its digits is 1944, while the sum is 25.

The square root of 639223 is about 799.5142275157. The cubic root of 639223 is about 86.1424985668.

The spelling of 639223 in words is "six hundred thirty-nine thousand, two hundred twenty-three".