161500217771 has 8 divisors (see below), whose sum is σ = 164022926400. Its totient is φ = 158996693632.

The previous prime is 161500217761. The next prime is 161500217839. The reversal of 161500217771 is 177712005161.

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 161500217771 - 2³⁰ = 160426475947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161500217701) 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, 4779155 + ... + 4812828.

It is an arithmetic number, because the mean of its divisors is an integer number (20502865800).

Almost surely, 2^161500217771 is an apocalyptic number.

161500217771 is a deficient number, since it is larger than the sum of its proper divisors (2522708629).

161500217771 is a wasteful number, since it uses less digits than its factorization.

161500217771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9592245.

The product of its (nonzero) digits is 20580, while the sum is 38.

The spelling of 161500217771 in words is "one hundred sixty-one billion, five hundred million, two hundred seventeen thousand, seven hundred seventy-one".