643586161 has 9 divisors (see below), whose sum is σ = 673395289. Its totient is φ = 615046036.

The previous prime is 643586159. The next prime is 643586171. The reversal of 643586161 is 161685346.

The square root of 643586161 is 25369.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 643586161 - 2¹ = 643586159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643586171) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 582936 + ... + 584038.

Almost surely, 2^643586161 is an apocalyptic number.

643586161 is the 25369-th square number.

643586161 is the 12685-th centered octagonal number.

It is an amenable number.

643586161 is a deficient number, since it is larger than the sum of its proper divisors (29809128).

643586161 is an frugal number, since it uses more digits than its factorization.

643586161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2252 (or 1126 counting only the distinct ones).

The product of its digits is 103680, while the sum is 40.

The cubic root of 643586161 is about 863.3804934245.

The spelling of 643586161 in words is "six hundred forty-three million, five hundred eighty-six thousand, one hundred sixty-one".