20366509 has 2 divisors, whose sum is σ = 20366510. Its totient is φ = 20366508.

The previous prime is 20366503. The next prime is 20366513. The reversal of 20366509 is 90566302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19386409 + 980100 = 4403^2 + 990^2 .

It is a cyclic number.

It is not a de Polignac number, because 20366509 - 2³ = 20366501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20366501) 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, 10183254 + 10183255.

It is an arithmetic number, because the mean of its divisors is an integer number (10183255).

Almost surely, 2^20366509 is an apocalyptic number.

It is an amenable number.

20366509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20366509 is an equidigital number, since it uses as much as digits as its factorization.

20366509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 20366509 is about 4512.9268773159. The cubic root of 20366509 is about 273.0898325486.

The spelling of 20366509 in words is "twenty million, three hundred sixty-six thousand, five hundred nine".