639732672 has 168 divisors, whose sum is σ = 1959644544. Its totient is φ = 199051776.

The previous prime is 639732619. The next prime is 639732689. The reversal of 639732672 is 276237936.

639732672 is a `hidden beast` number, since 639 + 7 + 3 + 2 + 6 + 7 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 569103 + ... + 570225.

Almost surely, 2^639732672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639732672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (979822272).

639732672 is an abundant number, since it is smaller than the sum of its proper divisors (1319911872).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639732672 is a wasteful number, since it uses less digits than its factorization.

639732672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1207 (or 1194 counting only the distinct ones).

The product of its digits is 571536, while the sum is 45.

The square root of 639732672 is about 25292.9371959842. The cubic root of 639732672 is about 861.6538716533.

The spelling of 639732672 in words is "six hundred thirty-nine million, seven hundred thirty-two thousand, six hundred seventy-two".