643603819 has 2 divisors, whose sum is σ = 643603820. Its totient is φ = 643603818.

The previous prime is 643603787. The next prime is 643603837. The reversal of 643603819 is 918306346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643603819 - 2⁵ = 643603787 is a prime.

It is a super-2 number, since 2×643603819² = 828451751662769522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (643603859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321801909 + 321801910.

It is an arithmetic number, because the mean of its divisors is an integer number (321801910).

Almost surely, 2^643603819 is an apocalyptic number.

643603819 is a deficient number, since it is larger than the sum of its proper divisors (1).

643603819 is an equidigital number, since it uses as much as digits as its factorization.

643603819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 643603819 is about 25369.3480207908. The cubic root of 643603819 is about 863.3883895096.

The spelling of 643603819 in words is "six hundred forty-three million, six hundred three thousand, eight hundred nineteen".