205128659 has 4 divisors (see below), whose sum is σ = 205205304. Its totient is φ = 205052016.

The previous prime is 205128611. The next prime is 205128661. The reversal of 205128659 is 956821502.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205128659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205128689) 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, 34157 + ... + 39710.

It is an arithmetic number, because the mean of its divisors is an integer number (51301326).

Almost surely, 2^205128659 is an apocalyptic number.

205128659 is a deficient number, since it is larger than the sum of its proper divisors (76645).

205128659 is an equidigital number, since it uses as much as digits as its factorization.

205128659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76644.

The product of its (nonzero) digits is 43200, while the sum is 38.

The square root of 205128659 is about 14322.3133257166. The cubic root of 205128659 is about 589.7601811890.

The spelling of 205128659 in words is "two hundred five million, one hundred twenty-eight thousand, six hundred fifty-nine".