161803161 has 24 divisors (see below), whose sum is σ = 266502600. Its totient is φ = 93712896.

The previous prime is 161803133. The next prime is 161803177. The reversal of 161803161 is 161308161.

It can be written as a sum of positive squares in 4 ways, for example, as 4761 + 161798400 = 69^2 + 12720^2 .

It is not a de Polignac number, because 161803161 - 2¹⁷ = 161672089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161803121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38686 + ... + 42663.

It is an arithmetic number, because the mean of its divisors is an integer number (11104275).

Almost surely, 2^161803161 is an apocalyptic number.

It is an amenable number.

161803161 is a deficient number, since it is larger than the sum of its proper divisors (104699439).

161803161 is a wasteful number, since it uses less digits than its factorization.

161803161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81385 (or 81382 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 161803161 is about 12720.1871448497. The cubic root of 161803161 is about 544.9152981179.

The spelling of 161803161 in words is "one hundred sixty-one million, eight hundred three thousand, one hundred sixty-one".