1643584161 has 4 divisors (see below), whose sum is σ = 2191445552. Its totient is φ = 1095722772.

The previous prime is 1643584147. The next prime is 1643584207. The reversal of 1643584161 is 1614853461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1643584161 - 2¹¹ = 1643582113 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1643584121) 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, 273930691 + ... + 273930696.

It is an arithmetic number, because the mean of its divisors is an integer number (547861388).

Almost surely, 2^1643584161 is an apocalyptic number.

It is an amenable number.

1643584161 is a deficient number, since it is larger than the sum of its proper divisors (547861391).

1643584161 is an equidigital number, since it uses as much as digits as its factorization.

1643584161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547861390.

The product of its digits is 69120, while the sum is 39.

The square root of 1643584161 is about 40541.1415848148. The cubic root of 1643584161 is about 1180.1321696730.

The spelling of 1643584161 in words is "one billion, six hundred forty-three million, five hundred eighty-four thousand, one hundred sixty-one".