261543742570555 has 8 divisors (see below), whose sum is σ = 327498251566752. Its totient is φ = 200137820401728.

The previous prime is 261543742570543. The next prime is 261543742570589. The reversal of 261543742570555 is 555075247345162.

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 261543742570555 - 2²⁵ = 261543709016123 is a prime.

It is a super-3 number, since 3×261543742570555³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261543742570493 and 261543742570502.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1137146706714 + ... + 1137146706943.

It is an arithmetic number, because the mean of its divisors is an integer number (40937281445844).

Almost surely, 2^{261543742570555} is an apocalyptic number.

261543742570555 is a deficient number, since it is larger than the sum of its proper divisors (65954508996197).

261543742570555 is a wasteful number, since it uses less digits than its factorization.

261543742570555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2274293413685.

The product of its (nonzero) digits is 176400000, while the sum is 61.

The spelling of 261543742570555 in words is "two hundred sixty-one trillion, five hundred forty-three billion, seven hundred forty-two million, five hundred seventy thousand, five hundred fifty-five".