261078387055507 has 32 divisors (see below), whose sum is σ = 303839249650560. Its totient is φ = 219697604536320.

The previous prime is 261078387055501. The next prime is 261078387055517. The reversal of 261078387055507 is 705550783870162.

It is a cyclic number.

It is not a de Polignac number, because 261078387055507 - 2¹¹ = 261078387053459 is a prime.

It is a Smith number, since the sum of its digits (64) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261078387055501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 789762969 + ... + 790093477.

It is an arithmetic number, because the mean of its divisors is an integer number (9494976551580).

Almost surely, 2^{261078387055507} is an apocalyptic number.

261078387055507 is a deficient number, since it is larger than the sum of its proper divisors (42760862595053).

261078387055507 is a wasteful number, since it uses less digits than its factorization.

261078387055507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334063.

The product of its (nonzero) digits is 98784000, while the sum is 64.

The spelling of 261078387055507 in words is "two hundred sixty-one trillion, seventy-eight billion, three hundred eighty-seven million, fifty-five thousand, five hundred seven".