161000643547 has 4 divisors (see below), whose sum is σ = 170471269656. Its totient is φ = 151530017440.

The previous prime is 161000643533. The next prime is 161000643569. The reversal of 161000643547 is 745346000161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161000643547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161000643527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4735313029 + ... + 4735313062.

It is an arithmetic number, because the mean of its divisors is an integer number (42617817414).

Almost surely, 2^161000643547 is an apocalyptic number.

161000643547 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

161000643547 is a deficient number, since it is larger than the sum of its proper divisors (9470626109).

161000643547 is an equidigital number, since it uses as much as digits as its factorization.

161000643547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9470626108.

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 161000643547 in words is "one hundred sixty-one billion, six hundred forty-three thousand, five hundred forty-seven".