261766447426801 has 8 divisors (see below), whose sum is σ = 269007887891304. Its totient is φ = 254533779152640.

The previous prime is 261766447426741. The next prime is 261766447426811. The reversal of 261766447426801 is 108624744667162.

It can be written as a sum of positive squares in 4 ways, for example, as 25819152375025 + 235947295051776 = 5081255^2 + 15360576^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261766447426801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261766447426811) 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 7 ways as a sum of consecutive naturals, for example, 2192987080 + ... + 2193106441.

It is an arithmetic number, because the mean of its divisors is an integer number (33625985986413).

Almost surely, 2^{261766447426801} is an apocalyptic number.

It is an amenable number.

261766447426801 is a deficient number, since it is larger than the sum of its proper divisors (7241440464503).

261766447426801 is a wasteful number, since it uses less digits than its factorization.

261766447426801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4386095171.

The product of its (nonzero) digits is 130056192, while the sum is 64.

The spelling of 261766447426801 in words is "two hundred sixty-one trillion, seven hundred sixty-six billion, four hundred forty-seven million, four hundred twenty-six thousand, eight hundred one".