643958352913 has 2 divisors, whose sum is σ = 643958352914. Its totient is φ = 643958352912.

The previous prime is 643958352899. The next prime is 643958352923. The reversal of 643958352913 is 319253859346.

643958352913 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 573038402049 + 70919950864 = 756993^2 + 266308^2 .

It is a cyclic number.

It is not a de Polignac number, because 643958352913 - 2⁵ = 643958352881 is a prime.

It is not a weakly prime, because it can be changed into another prime (643958352923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321979176456 + 321979176457.

It is an arithmetic number, because the mean of its divisors is an integer number (321979176457).

Almost surely, 2^643958352913 is an apocalyptic number.

It is an amenable number.

643958352913 is a deficient number, since it is larger than the sum of its proper divisors (1).

643958352913 is an equidigital number, since it uses as much as digits as its factorization.

643958352913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20995200, while the sum is 58.

The spelling of 643958352913 in words is "six hundred forty-three billion, nine hundred fifty-eight million, three hundred fifty-two thousand, nine hundred thirteen".