643348129 has 2 divisors, whose sum is σ = 643348130. Its totient is φ = 643348128.

The previous prime is 643348117. The next prime is 643348133. The reversal of 643348129 is 921843346.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 589178529 + 54169600 = 24273^2 + 7360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643348129 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 643348091 and 643348100.

It is not a weakly prime, because it can be changed into another prime (643348109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321674064 + 321674065.

It is an arithmetic number, because the mean of its divisors is an integer number (321674065).

Almost surely, 2^643348129 is an apocalyptic number.

It is an amenable number.

643348129 is a deficient number, since it is larger than the sum of its proper divisors (1).

643348129 is an equidigital number, since it uses as much as digits as its factorization.

643348129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 40.

The square root of 643348129 is about 25364.3081711290. The cubic root of 643348129 is about 863.2740391326.

The spelling of 643348129 in words is "six hundred forty-three million, three hundred forty-eight thousand, one hundred twenty-nine".