643041011 has 2 divisors, whose sum is σ = 643041012. Its totient is φ = 643041010.

The previous prime is 643040989. The next prime is 643041079. The reversal of 643041011 is 110140346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643041011 - 2¹⁸ = 642778867 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643041811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321520505 + 321520506.

It is an arithmetic number, because the mean of its divisors is an integer number (321520506).

Almost surely, 2^643041011 is an apocalyptic number.

643041011 is a deficient number, since it is larger than the sum of its proper divisors (1).

643041011 is an equidigital number, since it uses as much as digits as its factorization.

643041011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 643041011 is about 25358.2533112989. The cubic root of 643041011 is about 863.1366489266.

Adding to 643041011 its reverse (110140346), we get a palindrome (753181357).

The spelling of 643041011 in words is "six hundred forty-three million, forty-one thousand, eleven".