639566144 has 112 divisors (see below), whose sum is σ = 1538142720. Its totient is φ = 257748480.

The previous prime is 639566141. The next prime is 639566167. The reversal of 639566144 is 441665936.

It is a tau number, because it is divible by the number of its divisors (112).

It is a junction number, because it is equal to n+sod(n) for n = 639566095 and 639566104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639566141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1932059 + ... + 1932389.

Almost surely, 2^639566144 is an apocalyptic number.

639566144 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639566144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (769071360).

639566144 is an abundant number, since it is smaller than the sum of its proper divisors (898576576).

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

639566144 is a wasteful number, since it uses less digits than its factorization.

639566144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 596 (or 586 counting only the distinct ones).

The product of its digits is 466560, while the sum is 44.

The square root of 639566144 is about 25289.6449955313. The cubic root of 639566144 is about 861.5790998230.

The spelling of 639566144 in words is "six hundred thirty-nine million, five hundred sixty-six thousand, one hundred forty-four".