261660645701173 has 8 divisors (see below), whose sum is σ = 264372246815768. Its totient is φ = 258949331702784.

The previous prime is 261660645701167. The next prime is 261660645701197. The reversal of 261660645701173 is 371107546066162.

It can be written as a sum of positive squares in 4 ways, for example, as 28373114996164 + 233287530705009 = 5326642^2 + 15273753^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261660645701173 - 2¹³ = 261660645692981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261660645701113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69946686 + ... + 73592527.

It is an arithmetic number, because the mean of its divisors is an integer number (33046530851971).

Almost surely, 2^{261660645701173} is an apocalyptic number.

It is an amenable number.

261660645701173 is a deficient number, since it is larger than the sum of its proper divisors (2711601114595).

261660645701173 is a wasteful number, since it uses less digits than its factorization.

261660645701173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143558103.

The product of its (nonzero) digits is 7620480, while the sum is 55.

The spelling of 261660645701173 in words is "two hundred sixty-one trillion, six hundred sixty billion, six hundred forty-five million, seven hundred one thousand, one hundred seventy-three".