261646772641365 has 16 divisors (see below), whose sum is σ = 418661774044416. Its totient is φ = 139535966136000.

The previous prime is 261646772641361. The next prime is 261646772641391. The reversal of 261646772641365 is 563146277646162.

It is not a de Polignac number, because 261646772641365 - 2² = 261646772641361 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261646772641296 and 261646772641305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261646772641361) 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 in 15 ways as a sum of consecutive naturals, for example, 560963661 + ... + 561429890.

It is an arithmetic number, because the mean of its divisors is an integer number (26166360877776).

Almost surely, 2^{261646772641365} is an apocalyptic number.

It is an amenable number.

261646772641365 is a deficient number, since it is larger than the sum of its proper divisors (157015001403051).

261646772641365 is a wasteful number, since it uses less digits than its factorization.

261646772641365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122409100.

The product of its digits is 365783040, while the sum is 66.

The spelling of 261646772641365 in words is "two hundred sixty-one trillion, six hundred forty-six billion, seven hundred seventy-two million, six hundred forty-one thousand, three hundred sixty-five".