639255 has 16 divisors (see below), whose sum is σ = 1077120. Its totient is φ = 322848.

The previous prime is 639253. The next prime is 639257. The reversal of 639255 is 552936.

It is an interprime number because it is at equal distance from previous prime (639253) and next prime (639257).

It is not a de Polignac number, because 639255 - 2¹ = 639253 is a prime.

It is an Ulam number.

It is a nialpdrome in base 15.

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 polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 837 + ... + 1406.

It is an arithmetic number, because the mean of its divisors is an integer number (67320).

2⁶³⁹²⁵⁵ is an apocalyptic number.

639255 is a deficient number, since it is larger than the sum of its proper divisors (437865).

639255 is a wasteful number, since it uses less digits than its factorization.

639255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2270.

The product of its digits is 8100, while the sum is 30.

The square root of 639255 is about 799.5342394169. The cubic root of 639255 is about 86.1439359962.

The spelling of 639255 in words is "six hundred thirty-nine thousand, two hundred fifty-five".