201665325161 has 4 divisors (see below), whose sum is σ = 202530841812. Its totient is φ = 200799808512.

The previous prime is 201665325149. The next prime is 201665325221. The reversal of 201665325161 is 161523566102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15736197136 + 185929128025 = 125444^2 + 431195^2 .

It is a cyclic number.

It is not a de Polignac number, because 201665325161 - 2³⁰ = 200591583337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201665325761) 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, 432757976 + ... + 432758441.

It is an arithmetic number, because the mean of its divisors is an integer number (50632710453).

Almost surely, 2^201665325161 is an apocalyptic number.

It is an amenable number.

201665325161 is a deficient number, since it is larger than the sum of its proper divisors (865516651).

201665325161 is an equidigital number, since it uses as much as digits as its factorization.

201665325161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 865516650.

The product of its (nonzero) digits is 64800, while the sum is 38.

The spelling of 201665325161 in words is "two hundred one billion, six hundred sixty-five million, three hundred twenty-five thousand, one hundred sixty-one".