261535217441 has 8 divisors (see below), whose sum is σ = 265839456168. Its totient is φ = 257231520000.

The previous prime is 261535217429. The next prime is 261535217443. The reversal of 261535217441 is 144712535162.

It can be written as a sum of positive squares in 4 ways, for example, as 44491043041 + 217044174400 = 210929^2 + 465880^2 .

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 261535217441 - 2¹⁰ = 261535216417 is a prime.

It is a super-2 number, since 2×261535217441² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261535217443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 904121 + ... + 1157801.

It is an arithmetic number, because the mean of its divisors is an integer number (33229932021).

Almost surely, 2^261535217441 is an apocalyptic number.

It is an amenable number.

261535217441 is a deficient number, since it is larger than the sum of its proper divisors (4304238727).

261535217441 is a wasteful number, since it uses less digits than its factorization.

261535217441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270643.

The product of its digits is 201600, while the sum is 41.

The spelling of 261535217441 in words is "two hundred sixty-one billion, five hundred thirty-five million, two hundred seventeen thousand, four hundred forty-one".