639924042240 has 960 divisors, whose sum is σ = 2768711362560. Its totient is φ = 133205852160.

The previous prime is 639924042239. The next prime is 639924042259. The reversal of 639924042240 is 42240429936.

639924042240 is a `hidden beast` number, since 63 + 9 + 92 + 40 + 422 + 40 = 666.

639924042240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 84990796 + ... + 84998324.

It is an arithmetic number, because the mean of its divisors is an integer number (2884074336).

Almost surely, 2^639924042240 is an apocalyptic number.

639924042240 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 639924042240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1384355681280).

639924042240 is an abundant number, since it is smaller than the sum of its proper divisors (2128787320320).

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

639924042240 is a wasteful number, since it uses less digits than its factorization.

639924042240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7613 (or 7594 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 45.

The spelling of 639924042240 in words is "six hundred thirty-nine billion, nine hundred twenty-four million, forty-two thousand, two hundred forty".