205820161 has 8 divisors (see below), whose sum is σ = 210198848. Its totient is φ = 201474000.

The previous prime is 205820099. The next prime is 205820177. The reversal of 205820161 is 161028502.

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 205820161 - 2¹¹ = 205818113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205823161) 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, 4876 + ... + 20866.

It is an arithmetic number, because the mean of its divisors is an integer number (26274856).

Almost surely, 2^205820161 is an apocalyptic number.

It is an amenable number.

205820161 is a deficient number, since it is larger than the sum of its proper divisors (4378687).

205820161 is a wasteful number, since it uses less digits than its factorization.

205820161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16263.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 205820161 is about 14346.4337380410. The cubic root of 205820161 is about 590.4221444989.

Adding to 205820161 its reverse (161028502), we get a palindrome (366848663).

The spelling of 205820161 in words is "two hundred five million, eight hundred twenty thousand, one hundred sixty-one".