643165645 has 8 divisors (see below), whose sum is σ = 772704504. Its totient is φ = 513928704.

The previous prime is 643165613. The next prime is 643165651. The reversal of 643165645 is 546561346.

It can be written as a sum of positive squares in 4 ways, for example, as 166048996 + 477116649 = 12886^2 + 21843^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643165645 - 2⁵ = 643165613 is a prime.

It is a super-3 number, since 3×643165645³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643165598 and 643165607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70764 + ... + 79333.

It is an arithmetic number, because the mean of its divisors is an integer number (96588063).

Almost surely, 2^643165645 is an apocalyptic number.

It is an amenable number.

643165645 is a deficient number, since it is larger than the sum of its proper divisors (129538859).

643165645 is a wasteful number, since it uses less digits than its factorization.

643165645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150959.

The product of its digits is 259200, while the sum is 40.

The square root of 643165645 is about 25360.7106564465. The cubic root of 643165645 is about 863.1924096126.

The spelling of 643165645 in words is "six hundred forty-three million, one hundred sixty-five thousand, six hundred forty-five".