205951305 has 16 divisors (see below), whose sum is σ = 376596864. Its totient is φ = 94149120.

The previous prime is 205951297. The next prime is 205951309. The reversal of 205951305 is 503159502.

It is not a de Polignac number, because 205951305 - 2³ = 205951297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205951309) 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 15 ways as a sum of consecutive naturals, for example, 980616 + ... + 980825.

It is an arithmetic number, because the mean of its divisors is an integer number (23537304).

Almost surely, 2^205951305 is an apocalyptic number.

It is an amenable number.

205951305 is a deficient number, since it is larger than the sum of its proper divisors (170645559).

205951305 is a wasteful number, since it uses less digits than its factorization.

205951305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1961456.

The product of its (nonzero) digits is 6750, while the sum is 30.

The square root of 205951305 is about 14351.0036234404. The cubic root of 205951305 is about 590.5475191326.

It can be divided in two parts, 205 and 951305, that added together give a triangular number (951510 = T₁₃₇₉).

The spelling of 205951305 in words is "two hundred five million, nine hundred fifty-one thousand, three hundred five".