639040360 has 72 divisors (see below), whose sum is σ = 1675524690. Its totient is φ = 218715840.

The previous prime is 639040333. The next prime is 639040361. The reversal of 639040360 is 63040936.

It can be written as a sum of positive squares in only one way, i.e., 575136324 + 63904036 = 23982^2 + 7994^2 .

It is not an unprimeable number, because it can be changed into a prime (639040361) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1118875 + ... + 1119445.

Almost surely, 2^639040360 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 639040360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (837762345).

639040360 is an abundant number, since it is smaller than the sum of its proper divisors (1036484330).

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

639040360 is an equidigital number, since it uses as much as digits as its factorization.

639040360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1167 (or 585 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 31.

The square root of 639040360 is about 25279.2476153860. The cubic root of 639040360 is about 861.3429351959.

The spelling of 639040360 in words is "six hundred thirty-nine million, forty thousand, three hundred sixty".