639196678 has 16 divisors (see below), whose sum is σ = 976426560. Its totient is φ = 313736616.

The previous prime is 639196673. The next prime is 639196697. The reversal of 639196678 is 876691936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639196673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89425 + ... + 96307.

It is an arithmetic number, because the mean of its divisors is an integer number (61026660).

Almost surely, 2^639196678 is an apocalyptic number.

639196678 is a deficient number, since it is larger than the sum of its proper divisors (337229882).

639196678 is a wasteful number, since it uses less digits than its factorization.

639196678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7731.

The product of its digits is 2939328, while the sum is 55.

The square root of 639196678 is about 25282.3392509475. The cubic root of 639196678 is about 861.4131615521.

The spelling of 639196678 in words is "six hundred thirty-nine million, one hundred ninety-six thousand, six hundred seventy-eight".