20306243 has 2 divisors, whose sum is σ = 20306244. Its totient is φ = 20306242.

The previous prime is 20306233. The next prime is 20306257. The reversal of 20306243 is 34260302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20306243 - 2⁴ = 20306227 is a prime.

It is not a weakly prime, because it can be changed into another prime (20306203) 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, 10153121 + 10153122.

It is an arithmetic number, because the mean of its divisors is an integer number (10153122).

Almost surely, 2^20306243 is an apocalyptic number.

20306243 is a deficient number, since it is larger than the sum of its proper divisors (1).

20306243 is an equidigital number, since it uses as much as digits as its factorization.

20306243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 20306243 is about 4506.2448890401. The cubic root of 20306243 is about 272.8202021127.

Adding to 20306243 its reverse (34260302), we get a palindrome (54566545).

The spelling of 20306243 in words is "twenty million, three hundred six thousand, two hundred forty-three".