643730 has 8 divisors (see below), whose sum is σ = 1158732. Its totient is φ = 257488.

The previous prime is 643729. The next prime is 643751. The reversal of 643730 is 37346.

It can be written as a sum of positive squares in 2 ways, for example, as 638401 + 5329 = 799^2 + 73^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 643696 and 643705.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32177 + ... + 32196.

2⁶⁴³⁷³⁰ is an apocalyptic number.

643730 is a deficient number, since it is larger than the sum of its proper divisors (515002).

643730 is a wasteful number, since it uses less digits than its factorization.

643730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64380.

The product of its (nonzero) digits is 1512, while the sum is 23.

The square root of 643730 is about 802.3278631582. The cubic root of 643730 is about 86.3444809359.

The spelling of 643730 in words is "six hundred forty-three thousand, seven hundred thirty".