643702 has 4 divisors (see below), whose sum is σ = 965556. Its totient is φ = 321850.

The previous prime is 643697. The next prime is 643703. The reversal of 643702 is 207346.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643703) by changing a digit.

643702 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 160924 + ... + 160927.

It is an arithmetic number, because the mean of its divisors is an integer number (241389).

2⁶⁴³⁷⁰² is an apocalyptic number.

643702 is a deficient number, since it is larger than the sum of its proper divisors (321854).

643702 is a wasteful number, since it uses less digits than its factorization.

643702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321853.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 643702 is about 802.3104137427. The cubic root of 643702 is about 86.3432290236.

The spelling of 643702 in words is "six hundred forty-three thousand, seven hundred two".