261543742263365 has 8 divisors (see below), whose sum is σ = 315605856587040. Its totient is φ = 208066083230032.

The previous prime is 261543742263361. The next prime is 261543742263371. The reversal of 261543742263365 is 563362247345162.

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 261543742263365 - 2² = 261543742263361 is a prime.

It is a super-2 number, since 2×261543742263365² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261543742263361) 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, 146113821599 + ... + 146113823388.

It is an arithmetic number, because the mean of its divisors is an integer number (39450732073380).

Almost surely, 2^{261543742263365} is an apocalyptic number.

It is an amenable number.

261543742263365 is a deficient number, since it is larger than the sum of its proper divisors (54062114323675).

261543742263365 is a wasteful number, since it uses less digits than its factorization.

261543742263365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292227645171.

The product of its digits is 130636800, while the sum is 59.

The spelling of 261543742263365 in words is "two hundred sixty-one trillion, five hundred forty-three billion, seven hundred forty-two million, two hundred sixty-three thousand, three hundred sixty-five".