639123 has 8 divisors (see below), whose sum is σ = 858048. Its totient is φ = 423144.

The previous prime is 639091. The next prime is 639137. The reversal of 639123 is 321936.

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

It is not a de Polignac number, because 639123 - 2⁵ = 639091 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

639123 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 639093 and 639102.

It is not an unprimeable number, because it can be changed into a prime (639143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165 + ... + 1142.

It is an arithmetic number, because the mean of its divisors is an integer number (107256).

2⁶³⁹¹²³ is an apocalyptic number.

639123 is a deficient number, since it is larger than the sum of its proper divisors (218925).

639123 is a wasteful number, since it uses less digits than its factorization.

639123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1473.

The product of its digits is 972, while the sum is 24.

The square root of 639123 is about 799.4516870956. The cubic root of 639123 is about 86.1380062904.

The spelling of 639123 in words is "six hundred thirty-nine thousand, one hundred twenty-three".