20485009 has 2 divisors, whose sum is σ = 20485010. Its totient is φ = 20485008.

The previous prime is 20485007. The next prime is 20485033. The reversal of 20485009 is 90058402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18249984 + 2235025 = 4272^2 + 1495^2 .

It is a cyclic number.

It is not a de Polignac number, because 20485009 - 2¹ = 20485007 is a prime.

Together with 20485007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20485007) 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, 10242504 + 10242505.

It is an arithmetic number, because the mean of its divisors is an integer number (10242505).

Almost surely, 2^20485009 is an apocalyptic number.

It is an amenable number.

20485009 is a deficient number, since it is larger than the sum of its proper divisors (1).

20485009 is an equidigital number, since it uses as much as digits as its factorization.

20485009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 20485009 is about 4526.0367873008. The cubic root of 20485009 is about 273.6184550394.

The spelling of 20485009 in words is "twenty million, four hundred eighty-five thousand, nine".