20019209 has 8 divisors (see below), whose sum is σ = 23411520. Its totient is φ = 16760016.

The previous prime is 20019203. The next prime is 20019221. The reversal of 20019209 is 90291002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20019209 - 2⁸ = 20018953 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20019203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32954 + ... + 33555.

It is an arithmetic number, because the mean of its divisors is an integer number (2926440).

Almost surely, 2^20019209 is an apocalyptic number.

It is an amenable number.

20019209 is a deficient number, since it is larger than the sum of its proper divisors (3392311).

20019209 is an equidigital number, since it uses as much as digits as its factorization.

20019209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66559.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 20019209 is about 4474.2830710629. The cubic root of 20019209 is about 271.5286359326.

The spelling of 20019209 in words is "twenty million, nineteen thousand, two hundred nine".