643734000 has 640 divisors, whose sum is σ = 2859816960. Its totient is φ = 134784000.

The previous prime is 643733999. The next prime is 643734011. The reversal of 643734000 is 437346.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4913935 + ... + 4914065.

It is an arithmetic number, because the mean of its divisors is an integer number (4468464).

Almost surely, 2^643734000 is an apocalyptic number.

643734000 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 643734000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1429908480).

643734000 is an abundant number, since it is smaller than the sum of its proper divisors (2216082960).

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

643734000 is a wasteful number, since it uses less digits than its factorization.

643734000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 27.

The square root of 643734000 is about 25371.9136054023. The cubic root of 643734000 is about 863.4465977755.

The spelling of 643734000 in words is "six hundred forty-three million, seven hundred thirty-four thousand".