261774120540241 has 4 divisors (see below), whose sum is σ = 264175717976500. Its totient is φ = 259372523103984.

The previous prime is 261774120540239. The next prime is 261774120540353. The reversal of 261774120540241 is 142045021477162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 180499117520016 + 81275003020225 = 13434996^2 + 9015265^2 .

It is a cyclic number.

It is not a de Polignac number, because 261774120540241 - 2¹ = 261774120540239 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261774120540191 and 261774120540200.

It is not an unprimeable number, because it can be changed into a prime (261774120540221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1200798717966 + ... + 1200798718183.

It is an arithmetic number, because the mean of its divisors is an integer number (66043929494125).

Almost surely, 2^{261774120540241} is an apocalyptic number.

It is an amenable number.

261774120540241 is a deficient number, since it is larger than the sum of its proper divisors (2401597436259).

261774120540241 is a wasteful number, since it uses less digits than its factorization.

261774120540241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2401597436258.

The product of its (nonzero) digits is 752640, while the sum is 46.

The spelling of 261774120540241 in words is "two hundred sixty-one trillion, seven hundred seventy-four billion, one hundred twenty million, five hundred forty thousand, two hundred forty-one".