639278079 has 8 divisors (see below), whose sum is σ = 929859072. Its totient is φ = 387441240.

The previous prime is 639278069. The next prime is 639278111. The reversal of 639278079 is 970872936.

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

It is not a de Polignac number, because 639278079 - 2¹¹ = 639276031 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639278069) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 9685999 + ... + 9686064.

It is an arithmetic number, because the mean of its divisors is an integer number (116232384).

Almost surely, 2^639278079 is an apocalyptic number.

639278079 is a deficient number, since it is larger than the sum of its proper divisors (290580993).

639278079 is a wasteful number, since it uses less digits than its factorization.

639278079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19372077.

The product of its (nonzero) digits is 1143072, while the sum is 51.

The square root of 639278079 is about 25283.9490388665. The cubic root of 639278079 is about 861.4497266756.

The spelling of 639278079 in words is "six hundred thirty-nine million, two hundred seventy-eight thousand, seventy-nine".