206513161 has 4 divisors (see below), whose sum is σ = 218661012. Its totient is φ = 194365312.

The previous prime is 206513149. The next prime is 206513173. The reversal of 206513161 is 161315602.

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

It is an interprime number because it is at equal distance from previous prime (206513149) and next prime (206513173).

It can be written as a sum of positive squares in 2 ways, for example, as 55591936 + 150921225 = 7456^2 + 12285^2 .

It is a cyclic number.

It is not a de Polignac number, because 206513161 - 2¹¹ = 206511113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206513191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6073900 + ... + 6073933.

It is an arithmetic number, because the mean of its divisors is an integer number (54665253).

Almost surely, 2^206513161 is an apocalyptic number.

It is an amenable number.

206513161 is a deficient number, since it is larger than the sum of its proper divisors (12147851).

206513161 is a wasteful number, since it uses less digits than its factorization.

206513161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12147850.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 206513161 is about 14370.5657856606. The cubic root of 206513161 is about 591.0840559821.

Adding to 206513161 its reverse (161315602), we get a palindrome (367828763).

The spelling of 206513161 in words is "two hundred six million, five hundred thirteen thousand, one hundred sixty-one".