639022 has 4 divisors (see below), whose sum is σ = 958536. Its totient is φ = 319510.

The previous prime is 639011. The next prime is 639043. The reversal of 639022 is 220936.

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

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 638984 and 639002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159754 + ... + 159757.

It is an arithmetic number, because the mean of its divisors is an integer number (239634).

2⁶³⁹⁰²² is an apocalyptic number.

639022 is a deficient number, since it is larger than the sum of its proper divisors (319514).

639022 is a wasteful number, since it uses less digits than its factorization.

639022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319513.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 639022 is about 799.3885163048. The cubic root of 639022 is about 86.1334686156.

Adding to 639022 its reverse (220936), we get a palindrome (859958).

The spelling of 639022 in words is "six hundred thirty-nine thousand, twenty-two".