261535776416321 has 8 divisors (see below), whose sum is σ = 285353004078144. Its totient is φ = 237725423419120.

The previous prime is 261535776416261. The next prime is 261535776416347. The reversal of 261535776416321 is 123614677535162.

It is a happy number.

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 261535776416321 - 2²² = 261535772222017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261535776416021) 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, 1718586605 + ... + 1718738778.

It is an arithmetic number, because the mean of its divisors is an integer number (35669125509768).

Almost surely, 2^{261535776416321} is an apocalyptic number.

It is an amenable number.

261535776416321 is a deficient number, since it is larger than the sum of its proper divisors (23817227661823).

261535776416321 is a wasteful number, since it uses less digits than its factorization.

261535776416321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3437332311.

The product of its digits is 38102400, while the sum is 59.

The spelling of 261535776416321 in words is "two hundred sixty-one trillion, five hundred thirty-five billion, seven hundred seventy-six million, four hundred sixteen thousand, three hundred twenty-one".