261543742517575 has 24 divisors (see below), whose sum is σ = 372087044449632. Its totient is φ = 178646442885120.

The previous prime is 261543742517513. The next prime is 261543742517581. The reversal of 261543742517575 is 575715247345162.

It is not a de Polignac number, because 261543742517575 - 2¹³ = 261543742509383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 2907611974 + ... + 2907701923.

It is an arithmetic number, because the mean of its divisors is an integer number (15503626852068).

Almost surely, 2^{261543742517575} is an apocalyptic number.

261543742517575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

261543742517575 is a deficient number, since it is larger than the sum of its proper divisors (110543301932057).

261543742517575 is a wasteful number, since it uses less digits than its factorization.

261543742517575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5815314171 (or 5815314166 counting only the distinct ones).

The product of its digits is 246960000, while the sum is 64.

The spelling of 261543742517575 in words is "two hundred sixty-one trillion, five hundred forty-three billion, seven hundred forty-two million, five hundred seventeen thousand, five hundred seventy-five".