643747862016 has 640 divisors, whose sum is σ = 2260826726400. Its totient is φ = 177038991360.

The previous prime is 643747861997. The next prime is 643747862033. The reversal of 643747862016 is 610268747346.

643747862016 is a `hidden beast` number, since 6 + 4 + 3 + 7 + 4 + 7 + 8 + 620 + 1 + 6 = 666.

It is a super-2 number, since 2×643747862016² (a number of 24 digits) contains 22 as substring.

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

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 295431615 + ... + 295433793.

It is an arithmetic number, because the mean of its divisors is an integer number (3532541760).

Almost surely, 2^643747862016 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 643747862016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1130413363200).

643747862016 is an abundant number, since it is smaller than the sum of its proper divisors (1617078864384).

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

643747862016 is a wasteful number, since it uses less digits than its factorization.

643747862016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2327 (or 2305 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 54.

The spelling of 643747862016 in words is "six hundred forty-three billion, seven hundred forty-seven million, eight hundred sixty-two thousand, sixteen".