261543736375205 has 16 divisors (see below), whose sum is σ = 316798168357440. Its totient is φ = 207271353418752.

The previous prime is 261543736375121. The next prime is 261543736375213. The reversal of 261543736375205 is 502573637345162.

It is a cyclic number.

It is not a de Polignac number, because 261543736375205 - 2⁴⁰ = 260444224747429 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3973862 + ... + 23213768.

It is an arithmetic number, because the mean of its divisors is an integer number (19799885522340).

Almost surely, 2^{261543736375205} is an apocalyptic number.

It is an amenable number.

261543736375205 is a deficient number, since it is larger than the sum of its proper divisors (55254431982235).

261543736375205 is a wasteful number, since it uses less digits than its factorization.

261543736375205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19265428.

The product of its (nonzero) digits is 95256000, while the sum is 59.

The spelling of 261543736375205 in words is "two hundred sixty-one trillion, five hundred forty-three billion, seven hundred thirty-six million, three hundred seventy-five thousand, two hundred five".