20565247 has 2 divisors, whose sum is σ = 20565248. Its totient is φ = 20565246.

The previous prime is 20565211. The next prime is 20565271. The reversal of 20565247 is 74256502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20565247 - 2¹⁹ = 20040959 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20560247) 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, 10282623 + 10282624.

It is an arithmetic number, because the mean of its divisors is an integer number (10282624).

Almost surely, 2^20565247 is an apocalyptic number.

20565247 is a deficient number, since it is larger than the sum of its proper divisors (1).

20565247 is an equidigital number, since it uses as much as digits as its factorization.

20565247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 20565247 is about 4534.8921707137. The cubic root of 20565247 is about 273.9752361870.

The spelling of 20565247 in words is "twenty million, five hundred sixty-five thousand, two hundred forty-seven".