20505449 has 2 divisors, whose sum is σ = 20505450. Its totient is φ = 20505448.

The previous prime is 20505431. The next prime is 20505467. The reversal of 20505449 is 94450502.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (20505431) and next prime (20505467).

It can be written as a sum of positive squares in only one way, i.e., 15960025 + 4545424 = 3995^2 + 2132^2 .

It is a cyclic number.

It is not a de Polignac number, because 20505449 - 2⁸ = 20505193 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20505409) 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, 10252724 + 10252725.

It is an arithmetic number, because the mean of its divisors is an integer number (10252725).

Almost surely, 2^20505449 is an apocalyptic number.

It is an amenable number.

20505449 is a deficient number, since it is larger than the sum of its proper divisors (1).

20505449 is an equidigital number, since it uses as much as digits as its factorization.

20505449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 20505449 is about 4528.2942704732. The cubic root of 20505449 is about 273.7094305440.

The spelling of 20505449 in words is "twenty million, five hundred five thousand, four hundred forty-nine".