639427488 has 96 divisors (see below), whose sum is σ = 1970204544. Its totient is φ = 177748992.

The previous prime is 639427487. The next prime is 639427493. The reversal of 639427488 is 884724936.

It is a tau number, because it is divible by the number of its divisors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 639427488.

It is not an unprimeable number, because it can be changed into a prime (639427487) 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 15 ways as a sum of consecutive naturals, for example, 12006 + ... + 37722.

It is an arithmetic number, because the mean of its divisors is an integer number (20522964).

Almost surely, 2^639427488 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 639427488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (985102272).

639427488 is an abundant number, since it is smaller than the sum of its proper divisors (1330777056).

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

639427488 is a wasteful number, since it uses less digits than its factorization.

639427488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25774 (or 25766 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 51.

The square root of 639427488 is about 25286.9034877741. The cubic root of 639427488 is about 861.5168327446.

The spelling of 639427488 in words is "six hundred thirty-nine million, four hundred twenty-seven thousand, four hundred eighty-eight".