639176947 has 4 divisors (see below), whose sum is σ = 639716616. Its totient is φ = 638637280.

The previous prime is 639176917. The next prime is 639176957. The reversal of 639176947 is 749671936.

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

It is a cyclic number.

It is not a de Polignac number, because 639176947 - 2⁷ = 639176819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639176894 and 639176903.

It is not an unprimeable number, because it can be changed into a prime (639176917) 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 3 ways as a sum of consecutive naturals, for example, 268054 + ... + 270427.

It is an arithmetic number, because the mean of its divisors is an integer number (159929154).

Almost surely, 2^639176947 is an apocalyptic number.

639176947 is a deficient number, since it is larger than the sum of its proper divisors (539669).

639176947 is a wasteful number, since it uses less digits than its factorization.

639176947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539668.

The product of its digits is 1714608, while the sum is 52.

The square root of 639176947 is about 25281.9490348351. The cubic root of 639176947 is about 861.4042979694.

It can be divided in two parts, 6391 and 76947, that added together give a palindrome (83338).

The spelling of 639176947 in words is "six hundred thirty-nine million, one hundred seventy-six thousand, nine hundred forty-seven".