639171632 has 80 divisors (see below), whose sum is σ = 1399222944. Its totient is φ = 280320000.

The previous prime is 639171619. The next prime is 639171641. The reversal of 639171632 is 236171936.

It is a happy number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 728378 + ... + 729254.

Almost surely, 2^639171632 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 639171632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (699611472).

639171632 is an abundant number, since it is smaller than the sum of its proper divisors (760051312).

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

639171632 is a wasteful number, since it uses less digits than its factorization.

639171632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1038 (or 1032 counting only the distinct ones).

The product of its digits is 40824, while the sum is 38.

The square root of 639171632 is about 25281.8439200941. The cubic root of 639171632 is about 861.4019103277.

It can be divided in two parts, 639 and 171632, that added together give a palindrome (172271).

The spelling of 639171632 in words is "six hundred thirty-nine million, one hundred seventy-one thousand, six hundred thirty-two".