643946516352 has 384 divisors, whose sum is σ = 2074415616000. Its totient is φ = 198230022144.

The previous prime is 643946516303. The next prime is 643946516377. The reversal of 643946516352 is 253615649346.

643946516352 is a `hidden beast` number, since 6 + 4 + 3 + 94 + 6 + 516 + 35 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20730849 + ... + 20761887.

It is an arithmetic number, because the mean of its divisors is an integer number (5402124000).

Almost surely, 2^643946516352 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 643946516352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1037207808000).

643946516352 is an abundant number, since it is smaller than the sum of its proper divisors (1430469099648).

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

643946516352 is a wasteful number, since it uses less digits than its factorization.

643946516352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31120 (or 31096 counting only the distinct ones).

The product of its digits is 13996800, while the sum is 54.

The spelling of 643946516352 in words is "six hundred forty-three billion, nine hundred forty-six million, five hundred sixteen thousand, three hundred fifty-two".