643737574368 has 384 divisors, whose sum is σ = 2273951232000. Its totient is φ = 173249556480.

The previous prime is 643737574351. The next prime is 643737574399. The reversal of 643737574368 is 863475737346.

It is a happy number.

643737574368 is a `hidden beast` number, since 6 + 437 + 3 + 75 + 74 + 3 + 68 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7146313 + ... + 7235831.

It is an arithmetic number, because the mean of its divisors is an integer number (5921748000).

Almost surely, 2^643737574368 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 643737574368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1136975616000).

643737574368 is an abundant number, since it is smaller than the sum of its proper divisors (1630213657632).

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

643737574368 is a wasteful number, since it uses less digits than its factorization.

643737574368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89615 (or 89601 counting only the distinct ones).

The product of its digits is 213373440, while the sum is 63.

The spelling of 643737574368 in words is "six hundred forty-three billion, seven hundred thirty-seven million, five hundred seventy-four thousand, three hundred sixty-eight".