639204913680 has 160 divisors (see below), whose sum is σ = 2103109142400. Its totient is φ = 160044589056.

The previous prime is 639204913673. The next prime is 639204913703. The reversal of 639204913680 is 86319402936.

It is a super-2 number, since 2×639204913680² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1522566 + ... + 1896474.

It is an arithmetic number, because the mean of its divisors is an integer number (13144432140).

Almost surely, 2^639204913680 is an apocalyptic number.

639204913680 is a gapful number since it is divisible by the number (60) 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 639204913680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1051554571200).

639204913680 is an abundant number, since it is smaller than the sum of its proper divisors (1463904228720).

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

639204913680 is a wasteful number, since it uses less digits than its factorization.

639204913680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374361 (or 374355 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 51.

The spelling of 639204913680 in words is "six hundred thirty-nine billion, two hundred four million, nine hundred thirteen thousand, six hundred eighty".