161500555599 has 4 divisors (see below), whose sum is σ = 215334074136. Its totient is φ = 107667037064.

The previous prime is 161500555583. The next prime is 161500555613. The reversal of 161500555599 is 995555005161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 995555005161 = 3 ⋅331851668387.

It is a cyclic number.

It is not a de Polignac number, because 161500555599 - 2⁴ = 161500555583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161500555519) 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, 26916759264 + ... + 26916759269.

It is an arithmetic number, because the mean of its divisors is an integer number (53833518534).

Almost surely, 2^161500555599 is an apocalyptic number.

161500555599 is a deficient number, since it is larger than the sum of its proper divisors (53833518537).

161500555599 is an equidigital number, since it uses as much as digits as its factorization.

161500555599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53833518536.

The product of its (nonzero) digits is 1518750, while the sum is 51.

The spelling of 161500555599 in words is "one hundred sixty-one billion, five hundred million, five hundred fifty-five thousand, five hundred ninety-nine".