521785873823947 has 2 divisors, whose sum is σ = 521785873823948. Its totient is φ = 521785873823946.

The previous prime is 521785873823911. The next prime is 521785873823969. The reversal of 521785873823947 is 749328378587125.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521785873823947 - 2¹¹ = 521785873821899 is a prime.

It is not a weakly prime, because it can be changed into another prime (521785873829947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260892936911973 + 260892936911974.

It is an arithmetic number, because the mean of its divisors is an integer number (260892936911974).

Almost surely, 2^{521785873823947} is an apocalyptic number.

521785873823947 is a deficient number, since it is larger than the sum of its proper divisors (1).

521785873823947 is an equidigital number, since it uses as much as digits as its factorization.

521785873823947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5689958400, while the sum is 79.

The spelling of 521785873823947 in words is "five hundred twenty-one trillion, seven hundred eighty-five billion, eight hundred seventy-three million, eight hundred twenty-three thousand, nine hundred forty-seven".