205947649 has 4 divisors (see below), whose sum is σ = 206650836. Its totient is φ = 205244464.

The previous prime is 205947617. The next prime is 205947667. The reversal of 205947649 is 946749502.

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 97121025 + 108826624 = 9855^2 + 10432^2 .

It is a cyclic number.

It is not a de Polignac number, because 205947649 - 2⁵ = 205947617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205947599 and 205947608.

It is not an unprimeable number, because it can be changed into a prime (205947349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 351154 + ... + 351739.

It is an arithmetic number, because the mean of its divisors is an integer number (51662709).

Almost surely, 2^205947649 is an apocalyptic number.

It is an amenable number.

205947649 is a deficient number, since it is larger than the sum of its proper divisors (703187).

205947649 is an equidigital number, since it uses as much as digits as its factorization.

205947649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 703186.

The product of its (nonzero) digits is 544320, while the sum is 46.

The square root of 205947649 is about 14350.8762450242. The cubic root of 205947649 is about 590.5440246909.

The spelling of 205947649 in words is "two hundred five million, nine hundred forty-seven thousand, six hundred forty-nine".