161788066565 has 8 divisors (see below), whose sum is σ = 194151651840. Its totient is φ = 129426471952.

The previous prime is 161788066541. The next prime is 161788066567. The reversal of 161788066565 is 565660887161.

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 161788066565 - 2¹⁰ = 161788065541 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161788066567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 312605 + ... + 649074.

It is an arithmetic number, because the mean of its divisors is an integer number (24268956480).

Almost surely, 2^161788066565 is an apocalyptic number.

It is an amenable number.

161788066565 is a deficient number, since it is larger than the sum of its proper divisors (32363585275).

161788066565 is an equidigital number, since it uses as much as digits as its factorization.

161788066565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 995331.

The product of its (nonzero) digits is 14515200, while the sum is 59.

The spelling of 161788066565 in words is "one hundred sixty-one billion, seven hundred eighty-eight million, sixty-six thousand, five hundred sixty-five".