201720047 has 2 divisors, whose sum is σ = 201720048. Its totient is φ = 201720046.

The previous prime is 201719989. The next prime is 201720073. The reversal of 201720047 is 740027102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201720047 - 2¹⁸ = 201457903 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201720647) 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, 100860023 + 100860024.

It is an arithmetic number, because the mean of its divisors is an integer number (100860024).

Almost surely, 2^201720047 is an apocalyptic number.

201720047 is a deficient number, since it is larger than the sum of its proper divisors (1).

201720047 is an equidigital number, since it uses as much as digits as its factorization.

201720047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 201720047 is about 14202.8182766661. The cubic root of 201720047 is about 586.4752470725.

Adding to 201720047 its reverse (740027102), we get a palindrome (941747149).

The spelling of 201720047 in words is "two hundred one million, seven hundred twenty thousand, forty-seven".