20759909 has 2 divisors, whose sum is σ = 20759910. Its totient is φ = 20759908.

The previous prime is 20759891. The next prime is 20759957. The reversal of 20759909 is 90995702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10660225 + 10099684 = 3265^2 + 3178^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20759909 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20759509) 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, 10379954 + 10379955.

It is an arithmetic number, because the mean of its divisors is an integer number (10379955).

Almost surely, 2^20759909 is an apocalyptic number.

It is an amenable number.

20759909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20759909 is an equidigital number, since it uses as much as digits as its factorization.

20759909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51030, while the sum is 41.

The square root of 20759909 is about 4556.3043138052. The cubic root of 20759909 is about 274.8369678292.

The spelling of 20759909 in words is "twenty million, seven hundred fifty-nine thousand, nine hundred nine".