643166 has 8 divisors (see below), whose sum is σ = 968544. Its totient is φ = 320320.

The previous prime is 643129. The next prime is 643183. The reversal of 643166 is 661346.

643166 is nontrivially palindromic in base 5.

643166 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

643166 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251 + ... + 1161.

It is an arithmetic number, because the mean of its divisors is an integer number (121068).

2⁶⁴³¹⁶⁶ is an apocalyptic number.

643166 is a deficient number, since it is larger than the sum of its proper divisors (325378).

643166 is a wasteful number, since it uses less digits than its factorization.

643166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1266.

The product of its digits is 2592, while the sum is 26.

The square root of 643166 is about 801.9763088770. The cubic root of 643166 is about 86.3192568428.

The spelling of 643166 in words is "six hundred forty-three thousand, one hundred sixty-six".