206016661 has 4 divisors (see below), whose sum is σ = 206096800. Its totient is φ = 205936524.

The previous prime is 206016631. The next prime is 206016673. The reversal of 206016661 is 166610602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166610602 = 2 ⋅83305301.

It is a cyclic number.

It is not a de Polignac number, because 206016661 - 2²¹ = 203919509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206016631) 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, 36081 + ... + 41398.

It is an arithmetic number, because the mean of its divisors is an integer number (51524200).

Almost surely, 2^206016661 is an apocalyptic number.

It is an amenable number.

206016661 is a deficient number, since it is larger than the sum of its proper divisors (80139).

206016661 is an equidigital number, since it uses as much as digits as its factorization.

206016661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80138.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 206016661 is about 14353.2804961096. The cubic root of 206016661 is about 590.6099800814.

It can be divided in two parts, 2060 and 16661, that added together give a triangular number (18721 = T₁₉₃).

The spelling of 206016661 in words is "two hundred six million, sixteen thousand, six hundred sixty-one".