639106255 has 4 divisors (see below), whose sum is σ = 766927512. Its totient is φ = 511285000.

The previous prime is 639106201. The next prime is 639106271. The reversal of 639106255 is 552601936.

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

It is not a de Polignac number, because 639106255 - 2²¹ = 637009103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63910621 + ... + 63910630.

It is an arithmetic number, because the mean of its divisors is an integer number (191731878).

Almost surely, 2^639106255 is an apocalyptic number.

639106255 is a deficient number, since it is larger than the sum of its proper divisors (127821257).

639106255 is a wasteful number, since it uses less digits than its factorization.

639106255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127821256.

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 639106255 is about 25280.5509235855. The cubic root of 639106255 is about 861.3725401293.

The spelling of 639106255 in words is "six hundred thirty-nine million, one hundred six thousand, two hundred fifty-five".