639245600 has 144 divisors (see below), whose sum is σ = 1795260096. Its totient is φ = 217728000.

The previous prime is 639245599. The next prime is 639245603. The reversal of 639245600 is 6542936.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is not an unprimeable number, because it can be changed into a prime (639245603) by changing a digit.

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, 1181330 + ... + 1181870.

It is an arithmetic number, because the mean of its divisors is an integer number (12467084).

Almost surely, 2^639245600 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 639245600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (897630048).

639245600 is an abundant number, since it is smaller than the sum of its proper divisors (1156014496).

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

639245600 is a wasteful number, since it uses less digits than its factorization.

639245600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779 (or 766 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 639245600 is about 25283.3067457562. The cubic root of 639245600 is about 861.4351375631.

The spelling of 639245600 in words is "six hundred thirty-nine million, two hundred forty-five thousand, six hundred".