261565030844 has 72 divisors (see below), whose sum is σ = 500183728128. Its totient is φ = 119622484800.

The previous prime is 261565030829. The next prime is 261565030901. The reversal of 261565030844 is 448030565162.

It is a junction number, because it is equal to n+sod(n) for n = 261565030795 and 261565030804.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 98814329 + ... + 98816975.

It is an arithmetic number, because the mean of its divisors is an integer number (6946996224).

Almost surely, 2^261565030844 is an apocalyptic number.

It is an amenable number.

261565030844 is a deficient number, since it is larger than the sum of its proper divisors (238618697284).

261565030844 is a wasteful number, since it uses less digits than its factorization.

261565030844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3955 (or 3940 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 44.

The spelling of 261565030844 in words is "two hundred sixty-one billion, five hundred sixty-five million, thirty thousand, eight hundred forty-four".