20430517 has 2 divisors, whose sum is σ = 20430518. Its totient is φ = 20430516.

The previous prime is 20430503. The next prime is 20430539. The reversal of 20430517 is 71503402.

It is an a-pointer prime, because the next prime (20430539) can be obtained adding 20430517 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14447601 + 5982916 = 3801^2 + 2446^2 .

It is a cyclic number.

It is not a de Polignac number, because 20430517 - 2¹¹ = 20428469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20430577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215258 + 10215259.

It is an arithmetic number, because the mean of its divisors is an integer number (10215259).

Almost surely, 2^20430517 is an apocalyptic number.

It is an amenable number.

20430517 is a deficient number, since it is larger than the sum of its proper divisors (1).

20430517 is an equidigital number, since it uses as much as digits as its factorization.

20430517 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 20430517 is about 4520.0129424593. The cubic root of 20430517 is about 273.3756228770.

Adding to 20430517 its reverse (71503402), we get a palindrome (91933919).

The spelling of 20430517 in words is "twenty million, four hundred thirty thousand, five hundred seventeen".