643231 has 2 divisors, whose sum is σ = 643232. Its totient is φ = 643230.

The previous prime is 643217. The next prime is 643243. The reversal of 643231 is 132346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643231 - 2⁵ = 643199 is a prime.

It is a super-2 number, since 2×643231² = 827492238722, which contains 22 as substring.

It is equal to p₅₂₃₀₉ and since 643231 and 52309 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 643199 and 643208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643031) 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 as a sum of consecutive naturals, namely, 321615 + 321616.

It is an arithmetic number, because the mean of its divisors is an integer number (321616).

2⁶⁴³²³¹ is an apocalyptic number.

643231 is a deficient number, since it is larger than the sum of its proper divisors (1).

643231 is an equidigital number, since it uses as much as digits as its factorization.

643231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 19.

The square root of 643231 is about 802.0168327411. The cubic root of 643231 is about 86.3221646264.

Adding to 643231 its reverse (132346), we get a palindrome (775577).

The spelling of 643231 in words is "six hundred forty-three thousand, two hundred thirty-one".