639289 has 8 divisors (see below), whose sum is σ = 735488. Its totient is φ = 544320.

The previous prime is 639269. The next prime is 639299. The reversal of 639289 is 982936.

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

It is not a de Polignac number, because 639289 - 2⁵ = 639257 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (639259) 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, 1729 + ... + 2065.

It is an arithmetic number, because the mean of its divisors is an integer number (91936).

2⁶³⁹²⁸⁹ is an apocalyptic number.

It is an amenable number.

639289 is a deficient number, since it is larger than the sum of its proper divisors (96199).

639289 is a wasteful number, since it uses less digits than its factorization.

639289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615.

The product of its digits is 23328, while the sum is 37.

The square root of 639289 is about 799.5555015132. Note that the first 4 decimals coincide. The cubic root of 639289 is about 86.1454632125.

The spelling of 639289 in words is "six hundred thirty-nine thousand, two hundred eighty-nine".