639473180064 has 96 divisors (see below), whose sum is σ = 1700237952000. Its totient is φ = 210413409024.

The previous prime is 639473180057. The next prime is 639473180081. The reversal of 639473180064 is 460081374936.

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

It is a junction number, because it is equal to n+sod(n) for n = 639473179989 and 639473180016.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62327767 + ... + 62338025.

It is an arithmetic number, because the mean of its divisors is an integer number (17710812000).

Almost surely, 2^639473180064 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 639473180064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (850118976000).

639473180064 is an abundant number, since it is smaller than the sum of its proper divisors (1060764771936).

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

639473180064 is a wasteful number, since it uses less digits than its factorization.

639473180064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18570 (or 18562 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 51.

The spelling of 639473180064 in words is "six hundred thirty-nine billion, four hundred seventy-three million, one hundred eighty thousand, sixty-four".