643108515169 has 4 divisors (see below), whose sum is σ = 680938427844. Its totient is φ = 605278602496.

The previous prime is 643108515157. The next prime is 643108515187. The reversal of 643108515169 is 961515801346.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 961515801346 = 2 ⋅480757900673.

It can be written as a sum of positive squares in 2 ways, for example, as 258816387600 + 384292127569 = 508740^2 + 619913^2 .

It is a cyclic number.

It is not a de Polignac number, because 643108515169 - 2¹⁷ = 643108384097 is a prime.

It is a super-2 number, since 2×643108515169² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643108515109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18914956312 + ... + 18914956345.

It is an arithmetic number, because the mean of its divisors is an integer number (170234606961).

Almost surely, 2^643108515169 is an apocalyptic number.

It is an amenable number.

643108515169 is a deficient number, since it is larger than the sum of its proper divisors (37829912675).

643108515169 is a wasteful number, since it uses less digits than its factorization.

643108515169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37829912674.

The product of its (nonzero) digits is 777600, while the sum is 49.

The spelling of 643108515169 in words is "six hundred forty-three billion, one hundred eight million, five hundred fifteen thousand, one hundred sixty-nine".