204220161 has 6 divisors (see below), whose sum is σ = 294984690. Its totient is φ = 136146768.

The previous prime is 204220141. The next prime is 204220169. The reversal of 204220161 is 161022402.

It can be written as a sum of positive squares in only one way, i.e., 200760561 + 3459600 = 14169^2 + 1860^2 .

It is not a de Polignac number, because 204220161 - 2⁵ = 204220129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (204220169) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11345556 + ... + 11345573.

It is an arithmetic number, because the mean of its divisors is an integer number (49164115).

Almost surely, 2^204220161 is an apocalyptic number.

It is an amenable number.

204220161 is a deficient number, since it is larger than the sum of its proper divisors (90764529).

204220161 is a wasteful number, since it uses less digits than its factorization.

204220161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22691135 (or 22691132 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 204220161 is about 14290.5619553606. The cubic root of 204220161 is about 588.8882261625. Note that the first 3 decimals are identical.

Adding to 204220161 its reverse (161022402), we get a palindrome (365242563).

The spelling of 204220161 in words is "two hundred four million, two hundred twenty thousand, one hundred sixty-one".