639403384464 has 480 divisors, whose sum is σ = 2135747053440. Its totient is φ = 183440941056.

The previous prime is 639403384457. The next prime is 639403384553. The reversal of 639403384464 is 464483304936.

639403384464 is a `hidden beast` number, since 6 + 39 + 40 + 33 + 84 + 464 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 639403384464.

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, 93654619 + ... + 93661445.

It is an arithmetic number, because the mean of its divisors is an integer number (4449473028).

Almost surely, 2^639403384464 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 639403384464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1067873526720).

639403384464 is an abundant number, since it is smaller than the sum of its proper divisors (1496343668976).

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

639403384464 is a wasteful number, since it uses less digits than its factorization.

639403384464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6989 (or 6971 counting only the distinct ones).

The product of its (nonzero) digits is 17915904, while the sum is 54.

The spelling of 639403384464 in words is "six hundred thirty-nine billion, four hundred three million, three hundred eighty-four thousand, four hundred sixty-four".