639673063 has 4 divisors (see below), whose sum is σ = 639761760. Its totient is φ = 639584368.

The previous prime is 639673043. The next prime is 639673081. The reversal of 639673063 is 360376936.

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 639673063 - 2¹³ = 639664871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639673043) 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, 32470 + ... + 48307.

It is an arithmetic number, because the mean of its divisors is an integer number (159940440).

Almost surely, 2^639673063 is an apocalyptic number.

639673063 is a deficient number, since it is larger than the sum of its proper divisors (88697).

639673063 is an equidigital number, since it uses as much as digits as its factorization.

639673063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88696.

The product of its (nonzero) digits is 367416, while the sum is 43.

The square root of 639673063 is about 25291.7587960980. The cubic root of 639673063 is about 861.6271084321.

The spelling of 639673063 in words is "six hundred thirty-nine million, six hundred seventy-three thousand, sixty-three".