643748000 has 192 divisors, whose sum is σ = 1836027648. Its totient is φ = 217267200.

The previous prime is 643747999. The next prime is 643748029. The reversal of 643748000 is 847346.

It is a happy number.

It is a super-2 number, since 2×643748000² = 828822975008000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2323862 + ... + 2324138.

It is an arithmetic number, because the mean of its divisors is an integer number (9562644).

Almost surely, 2^643748000 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 643748000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (918013824).

643748000 is an abundant number, since it is smaller than the sum of its proper divisors (1192279648).

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

643748000 is a wasteful number, since it uses less digits than its factorization.

643748000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392 (or 374 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 643748000 is about 25372.1894995288. The cubic root of 643748000 is about 863.4528571749.

The spelling of 643748000 in words is "six hundred forty-three million, seven hundred forty-eight thousand".