643157760 has 288 divisors, whose sum is σ = 2387653632. Its totient is φ = 144506880.

The previous prime is 643157747. The next prime is 643157777. The reversal of 643157760 is 67751346.

It is a congruent number.

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, 1908312 + ... + 1908648.

It is an arithmetic number, because the mean of its divisors is an integer number (8290464).

Almost surely, 2^643157760 is an apocalyptic number.

643157760 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 643157760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1193826816).

643157760 is an abundant number, since it is smaller than the sum of its proper divisors (1744495872).

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

643157760 is a wasteful number, since it uses less digits than its factorization.

643157760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439 (or 425 counting only the distinct ones).

The product of its (nonzero) digits is 105840, while the sum is 39.

The square root of 643157760 is about 25360.5551989699. Note that the first 3 decimals coincide. The cubic root of 643157760 is about 863.1888821129.

The spelling of 643157760 in words is "six hundred forty-three million, one hundred fifty-seven thousand, seven hundred sixty".