495991009 has 2 divisors, whose sum is σ = 495991010. Its totient is φ = 495991008.

The previous prime is 495990967. The next prime is 495991049. The reversal of 495991009 is 900199594.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 429649984 + 66341025 = 20728^2 + 8145^2 .

It is a cyclic number.

It is not a de Polignac number, because 495991009 - 2²¹ = 493893857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 495991009.

It is not a weakly prime, because it can be changed into another prime (495991049) 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, 247995504 + 247995505.

It is an arithmetic number, because the mean of its divisors is an integer number (247995505).

Almost surely, 2^495991009 is an apocalyptic number.

It is an amenable number.

495991009 is a deficient number, since it is larger than the sum of its proper divisors (1).

495991009 is an equidigital number, since it uses as much as digits as its factorization.

495991009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 131220, while the sum is 46.

The square root of 495991009 is about 22270.8555964965. The cubic root of 495991009 is about 791.5735389228.

The spelling of 495991009 in words is "four hundred ninety-five million, nine hundred ninety-one thousand, nine".