643548472069 has 2 divisors, whose sum is σ = 643548472070. Its totient is φ = 643548472068.

The previous prime is 643548472043. The next prime is 643548472079. The reversal of 643548472069 is 960274845346.

643548472069 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., 608696436100 + 34852035969 = 780190^2 + 186687^2 .

It is a cyclic number.

It is not a de Polignac number, because 643548472069 - 2⁵ = 643548472037 is a prime.

It is a super-2 number, since 2×643548472069² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643548472079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321774236034 + 321774236035.

It is an arithmetic number, because the mean of its divisors is an integer number (321774236035).

Almost surely, 2^643548472069 is an apocalyptic number.

It is an amenable number.

643548472069 is a deficient number, since it is larger than the sum of its proper divisors (1).

643548472069 is an equidigital number, since it uses as much as digits as its factorization.

643548472069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34836480, while the sum is 58.

The spelling of 643548472069 in words is "six hundred forty-three billion, five hundred forty-eight million, four hundred seventy-two thousand, sixty-nine".