991927569593 has 2 divisors, whose sum is σ = 991927569594. Its totient is φ = 991927569592.

The previous prime is 991927569583. The next prime is 991927569641. The reversal of 991927569593 is 395965729199.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 618860702329 + 373066867264 = 786677^2 + 610792^2 .

It is an emirp because it is prime and its reverse (395965729199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 991927569593 - 2¹⁴ = 991927553209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 991927569593.

It is not a weakly prime, because it can be changed into another prime (991927569583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495963784796 + 495963784797.

It is an arithmetic number, because the mean of its divisors is an integer number (495963784797).

Almost surely, 2^991927569593 is an apocalyptic number.

It is an amenable number.

991927569593 is a deficient number, since it is larger than the sum of its proper divisors (1).

991927569593 is an equidigital number, since it uses as much as digits as its factorization.

991927569593 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 372008700, while the sum is 74.

The spelling of 991927569593 in words is "nine hundred ninety-one billion, nine hundred twenty-seven million, five hundred sixty-nine thousand, five hundred ninety-three".