20243809 has 2 divisors, whose sum is σ = 20243810. Its totient is φ = 20243808.

The previous prime is 20243779. The next prime is 20243819. The reversal of 20243809 is 90834202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19998784 + 245025 = 4472^2 + 495^2 .

It is a cyclic number.

It is not a de Polignac number, because 20243809 - 2⁵ = 20243777 is a prime.

It is not a weakly prime, because it can be changed into another prime (20243819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10121904 + 10121905.

It is an arithmetic number, because the mean of its divisors is an integer number (10121905).

Almost surely, 2^20243809 is an apocalyptic number.

It is an amenable number.

20243809 is a deficient number, since it is larger than the sum of its proper divisors (1).

20243809 is an equidigital number, since it uses as much as digits as its factorization.

20243809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20243809 is about 4499.3120585263. The cubic root of 20243809 is about 272.5403088254.

The spelling of 20243809 in words is "twenty million, two hundred forty-three thousand, eight hundred nine".