20844709 has 2 divisors, whose sum is σ = 20844710. Its totient is φ = 20844708.

The previous prime is 20844701. The next prime is 20844713. The reversal of 20844709 is 90744802.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13527684 + 7317025 = 3678^2 + 2705^2 .

It is a cyclic number.

It is not a de Polignac number, because 20844709 - 2³ = 20844701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20844701) 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, 10422354 + 10422355.

It is an arithmetic number, because the mean of its divisors is an integer number (10422355).

Almost surely, 2^20844709 is an apocalyptic number.

It is an amenable number.

20844709 is a deficient number, since it is larger than the sum of its proper divisors (1).

20844709 is an equidigital number, since it uses as much as digits as its factorization.

20844709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 20844709 is about 4565.6006176625. The cubic root of 20844709 is about 275.2106771268.

The spelling of 20844709 in words is "twenty million, eight hundred forty-four thousand, seven hundred nine".