643548473069 has 2 divisors, whose sum is σ = 643548473070. Its totient is φ = 643548473068.

The previous prime is 643548473033. The next prime is 643548473107. The reversal of 643548473069 is 960374845346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 595618128169 + 47930344900 = 771763^2 + 218930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643548473069 is a prime.

It is a super-2 number, since 2×643548473069² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643548472999 and 643548473017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643548472069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321774236534 + 321774236535.

It is an arithmetic number, because the mean of its divisors is an integer number (321774236535).

Almost surely, 2^643548473069 is an apocalyptic number.

It is an amenable number.

643548473069 is a deficient number, since it is larger than the sum of its proper divisors (1).

643548473069 is an equidigital number, since it uses as much as digits as its factorization.

643548473069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52254720, while the sum is 59.

The spelling of 643548473069 in words is "six hundred forty-three billion, five hundred forty-eight million, four hundred seventy-three thousand, sixty-nine".