643758 has 16 divisors (see below), whose sum is σ = 1355520. Its totient is φ = 203256.

The previous prime is 643751. The next prime is 643781. The reversal of 643758 is 857346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2710 + ... + 2937.

It is an arithmetic number, because the mean of its divisors is an integer number (84720).

2⁶⁴³⁷⁵⁸ is an apocalyptic number.

643758 is an abundant number, since it is smaller than the sum of its proper divisors (711762).

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

643758 is a wasteful number, since it uses less digits than its factorization.

643758 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5671.

The product of its digits is 20160, while the sum is 33.

The square root of 643758 is about 802.3453121942. The cubic root of 643758 is about 86.3457328119.

The spelling of 643758 in words is "six hundred forty-three thousand, seven hundred fifty-eight".