643213 has 2 divisors, whose sum is σ = 643214. Its totient is φ = 643212.

The previous prime is 643199. The next prime is 643217. The reversal of 643213 is 312346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 643204 + 9 = 802^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 643213 - 2⁹ = 642701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321606 + 321607.

It is an arithmetic number, because the mean of its divisors is an integer number (321607).

2⁶⁴³²¹³ is an apocalyptic number.

It is an amenable number.

643213 is a deficient number, since it is larger than the sum of its proper divisors (1).

643213 is an equidigital number, since it uses as much as digits as its factorization.

643213 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 643213 is about 802.0056109529. The cubic root of 643213 is about 86.3213594136.

Adding to 643213 its reverse (312346), we get a palindrome (955559).

The spelling of 643213 in words is "six hundred forty-three thousand, two hundred thirteen".