643234 has 4 divisors (see below), whose sum is σ = 964854. Its totient is φ = 321616.

The previous prime is 643231. The next prime is 643243. The reversal of 643234 is 432346.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 432346 = 2 ⋅216173.

It can be written as a sum of positive squares in only one way, i.e., 555025 + 88209 = 745^2 + 297^2 .

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 not an unprimeable number, because it can be changed into a prime (643231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160807 + ... + 160810.

2⁶⁴³²³⁴ is an apocalyptic number.

643234 is a deficient number, since it is larger than the sum of its proper divisors (321620).

643234 is a wasteful number, since it uses less digits than its factorization.

643234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321619.

The product of its digits is 1728, while the sum is 22.

The square root of 643234 is about 802.0187030238. The cubic root of 643234 is about 86.3222988271.

The spelling of 643234 in words is "six hundred forty-three thousand, two hundred thirty-four".