261776666641 has 8 divisors (see below), whose sum is σ = 300238009344. Its totient is φ = 223581492960.

The previous prime is 261776666639. The next prime is 261776666647. The reversal of 261776666641 is 146666677162.

261776666641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 261776666641 - 2¹ = 261776666639 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261776666647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66540145 + ... + 66544078.

It is an arithmetic number, because the mean of its divisors is an integer number (37529751168).

Almost surely, 2^261776666641 is an apocalyptic number.

It is an amenable number.

261776666641 is a deficient number, since it is larger than the sum of its proper divisors (38461342703).

261776666641 is a wasteful number, since it uses less digits than its factorization.

261776666641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133084511.

The product of its digits is 18289152, while the sum is 58.

The spelling of 261776666641 in words is "two hundred sixty-one billion, seven hundred seventy-six million, six hundred sixty-six thousand, six hundred forty-one".