205716641 has 4 divisors (see below), whose sum is σ = 221541012. Its totient is φ = 189892272.

The previous prime is 205716631. The next prime is 205716653. The reversal of 205716641 is 146617502.

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

It can be written as a sum of positive squares in 2 ways, for example, as 110166016 + 95550625 = 10496^2 + 9775^2 .

It is a cyclic number.

It is not a de Polignac number, because 205716641 - 2¹⁸ = 205454497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 205716598 and 205716607.

It is not an unprimeable number, because it can be changed into a prime (205716611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7912166 + ... + 7912191.

It is an arithmetic number, because the mean of its divisors is an integer number (55385253).

Almost surely, 2^205716641 is an apocalyptic number.

It is an amenable number.

205716641 is a deficient number, since it is larger than the sum of its proper divisors (15824371).

205716641 is a wasteful number, since it uses less digits than its factorization.

205716641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15824370.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 205716641 is about 14342.8254190030. The cubic root of 205716641 is about 590.3231409965.

The spelling of 205716641 in words is "two hundred five million, seven hundred sixteen thousand, six hundred forty-one".