205900649 has 2 divisors, whose sum is σ = 205900650. Its totient is φ = 205900648.

The previous prime is 205900631. The next prime is 205900687. The reversal of 205900649 is 946009502.

205900649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192321424 + 13579225 = 13868^2 + 3685^2 .

It is a cyclic number.

It is not a de Polignac number, because 205900649 - 2²⁰ = 204852073 is a prime.

It is not a weakly prime, because it can be changed into another prime (205900049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102950324 + 102950325.

It is an arithmetic number, because the mean of its divisors is an integer number (102950325).

Almost surely, 2^205900649 is an apocalyptic number.

It is an amenable number.

205900649 is a deficient number, since it is larger than the sum of its proper divisors (1).

205900649 is an equidigital number, since it uses as much as digits as its factorization.

205900649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 205900649 is about 14349.2386209164. The cubic root of 205900649 is about 590.4990979325.

The spelling of 205900649 in words is "two hundred five million, nine hundred thousand, six hundred forty-nine".