205308986 has 4 divisors (see below), whose sum is σ = 307963482. Its totient is φ = 102654492.

The previous prime is 205308953. The next prime is 205308989. The reversal of 205308986 is 689803502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689803502 = 2 ⋅344901751.

It can be written as a sum of positive squares in only one way, i.e., 162078361 + 43230625 = 12731^2 + 6575^2 .

It is not an unprimeable number, because it can be changed into a prime (205308989) 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 as a sum of consecutive naturals, namely, 51327245 + ... + 51327248.

Almost surely, 2^205308986 is an apocalyptic number.

205308986 is a deficient number, since it is larger than the sum of its proper divisors (102654496).

205308986 is a wasteful number, since it uses less digits than its factorization.

205308986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102654495.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 205308986 is about 14328.6072596048. The cubic root of 205308986 is about 589.9329484272.

The spelling of 205308986 in words is "two hundred five million, three hundred eight thousand, nine hundred eighty-six".