643527680 has 176 divisors, whose sum is σ = 1642840320. Its totient is φ = 241532928.

The previous prime is 643527671. The next prime is 643527683. The reversal of 643527680 is 86725346.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643527683) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8145881 + ... + 8145959.

It is an arithmetic number, because the mean of its divisors is an integer number (9334320).

Almost surely, 2^643527680 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 643527680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (821420160).

643527680 is an abundant number, since it is smaller than the sum of its proper divisors (999312640).

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

643527680 is a wasteful number, since it uses less digits than its factorization.

643527680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 41.

The square root of 643527680 is about 25367.8473663021. The cubic root of 643527680 is about 863.3543415860.

The spelling of 643527680 in words is "six hundred forty-three million, five hundred twenty-seven thousand, six hundred eighty".