261516435809 has 8 divisors (see below), whose sum is σ = 263018316288. Its totient is φ = 260015937840.

The previous prime is 261516435787. The next prime is 261516435821. The reversal of 261516435809 is 908534615162.

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 261516435809 - 2¹⁶ = 261516370273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261516435839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34979 + ... + 724055.

It is an arithmetic number, because the mean of its divisors is an integer number (32877289536).

Almost surely, 2^261516435809 is an apocalyptic number.

It is an amenable number.

261516435809 is a deficient number, since it is larger than the sum of its proper divisors (1501880479).

261516435809 is a wasteful number, since it uses less digits than its factorization.

261516435809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 691255.

The product of its (nonzero) digits is 1555200, while the sum is 50.

The spelling of 261516435809 in words is "two hundred sixty-one billion, five hundred sixteen million, four hundred thirty-five thousand, eight hundred nine".