643545120 has 192 divisors, whose sum is σ = 2129863680. Its totient is φ = 163123200.

The previous prime is 643545101. The next prime is 643545121. The reversal of 643545120 is 21545346.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (643545121) by changing a digit.

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, 907326 + ... + 908034.

It is an arithmetic number, because the mean of its divisors is an integer number (11093040).

Almost surely, 2^643545120 is an apocalyptic number.

643545120 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 643545120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1064931840).

643545120 is an abundant number, since it is smaller than the sum of its proper divisors (1486318560).

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

643545120 is a wasteful number, since it uses less digits than its factorization.

643545120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819 (or 811 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 643545120 is about 25368.1911061865. The cubic root of 643545120 is about 863.3621406619.

The spelling of 643545120 in words is "six hundred forty-three million, five hundred forty-five thousand, one hundred twenty".