261576128393 has 2 divisors, whose sum is σ = 261576128394. Its totient is φ = 261576128392.

The previous prime is 261576128389. The next prime is 261576128419. The reversal of 261576128393 is 393821675162.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 255497899024 + 6078229369 = 505468^2 + 77963^2 .

It is a cyclic number.

It is not a de Polignac number, because 261576128393 - 2² = 261576128389 is a prime.

It is not a weakly prime, because it can be changed into another prime (261576128323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130788064196 + 130788064197.

It is an arithmetic number, because the mean of its divisors is an integer number (130788064197).

Almost surely, 2^261576128393 is an apocalyptic number.

It is an amenable number.

261576128393 is a deficient number, since it is larger than the sum of its proper divisors (1).

261576128393 is an equidigital number, since it uses as much as digits as its factorization.

261576128393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 53.

The spelling of 261576128393 in words is "two hundred sixty-one billion, five hundred seventy-six million, one hundred twenty-eight thousand, three hundred ninety-three".