20450009 has 2 divisors, whose sum is σ = 20450010. Its totient is φ = 20450008.

The previous prime is 20449999. The next prime is 20450033. The reversal of 20450009 is 90005402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15840400 + 4609609 = 3980^2 + 2147^2 .

It is a cyclic number.

It is not a de Polignac number, because 20450009 - 2⁴ = 20449993 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20453009) 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 as a sum of consecutive naturals, namely, 10225004 + 10225005.

It is an arithmetic number, because the mean of its divisors is an integer number (10225005).

Almost surely, 2^20450009 is an apocalyptic number.

It is an amenable number.

20450009 is a deficient number, since it is larger than the sum of its proper divisors (1).

20450009 is an equidigital number, since it uses as much as digits as its factorization.

20450009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20450009 is about 4522.1686169359. The cubic root of 20450009 is about 273.4625344306.

The spelling of 20450009 in words is "twenty million, four hundred fifty thousand, nine".