643429 has 2 divisors, whose sum is σ = 643430. Its totient is φ = 643428.

The previous prime is 643421. The next prime is 643439. The reversal of 643429 is 924346.

643429 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 643204 + 225 = 802^2 + 15^2 .

It is a cyclic number.

It is not a de Polignac number, because 643429 - 2³ = 643421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643397 and 643406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321714 + 321715.

It is an arithmetic number, because the mean of its divisors is an integer number (321715).

2⁶⁴³⁴²⁹ is an apocalyptic number.

It is an amenable number.

643429 is a deficient number, since it is larger than the sum of its proper divisors (1).

643429 is an equidigital number, since it uses as much as digits as its factorization.

643429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 28.

The square root of 643429 is about 802.1402620490. The cubic root of 643429 is about 86.3310209757.

The spelling of 643429 in words is "six hundred forty-three thousand, four hundred twenty-nine".