639608424 has 128 divisors (see below), whose sum is σ = 2000705280. Its totient is φ = 165888000.

The previous prime is 639608341. The next prime is 639608467. The reversal of 639608424 is 424806936.

It is a happy number.

639608424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 130824 + ... + 135624.

It is an arithmetic number, because the mean of its divisors is an integer number (15630510).

Almost surely, 2^639608424 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 639608424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1000352640).

639608424 is an abundant number, since it is smaller than the sum of its proper divisors (1361096856).

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

639608424 is a wasteful number, since it uses less digits than its factorization.

639608424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4891 (or 4887 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 42.

The square root of 639608424 is about 25290.4808969699. The cubic root of 639608424 is about 861.5980849647.

The spelling of 639608424 in words is "six hundred thirty-nine million, six hundred eight thousand, four hundred twenty-four".