205785771 has 8 divisors (see below), whose sum is σ = 274533840. Its totient is φ = 137114112.

The previous prime is 205785737. The next prime is 205785773. The reversal of 205785771 is 177587502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 205785771 - 2¹⁴ = 205769387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205785773) 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 7 ways as a sum of consecutive naturals, for example, 12490 + ... + 23823.

It is an arithmetic number, because the mean of its divisors is an integer number (34316730).

Almost surely, 2^205785771 is an apocalyptic number.

205785771 is a deficient number, since it is larger than the sum of its proper divisors (68748069).

205785771 is a wasteful number, since it uses less digits than its factorization.

205785771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38205.

The product of its (nonzero) digits is 137200, while the sum is 42.

The square root of 205785771 is about 14345.2351322660. The cubic root of 205785771 is about 590.3892585911.

The spelling of 205785771 in words is "two hundred five million, seven hundred eighty-five thousand, seven hundred seventy-one".