20544809 has 2 divisors, whose sum is σ = 20544810. Its totient is φ = 20544808.

The previous prime is 20544793. The next prime is 20544817. The reversal of 20544809 is 90844502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20502784 + 42025 = 4528^2 + 205^2 .

It is a cyclic number.

It is not a de Polignac number, because 20544809 - 2⁴ = 20544793 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20544889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10272404 + 10272405.

It is an arithmetic number, because the mean of its divisors is an integer number (10272405).

Almost surely, 2^20544809 is an apocalyptic number.

It is an amenable number.

20544809 is a deficient number, since it is larger than the sum of its proper divisors (1).

20544809 is an equidigital number, since it uses as much as digits as its factorization.

20544809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 20544809 is about 4532.6381942529. The cubic root of 20544809 is about 273.8844460974.

The spelling of 20544809 in words is "twenty million, five hundred forty-four thousand, eight hundred nine".