643370129 has 2 divisors, whose sum is σ = 643370130. Its totient is φ = 643370128.

The previous prime is 643370107. The next prime is 643370131. The reversal of 643370129 is 921073346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 527850625 + 115519504 = 22975^2 + 10748^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643370129 is a prime.

Together with 643370131, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643370159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321685064 + 321685065.

It is an arithmetic number, because the mean of its divisors is an integer number (321685065).

Almost surely, 2^643370129 is an apocalyptic number.

It is an amenable number.

643370129 is a deficient number, since it is larger than the sum of its proper divisors (1).

643370129 is an equidigital number, since it uses as much as digits as its factorization.

643370129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 35.

The square root of 643370129 is about 25364.7418476909. The cubic root of 643370129 is about 863.2838792235.

The spelling of 643370129 in words is "six hundred forty-three million, three hundred seventy thousand, one hundred twenty-nine".