261635040056 has 64 divisors (see below), whose sum is σ = 531744696000. Its totient is φ = 119968662528.

The previous prime is 261635040053. The next prime is 261635040067. The reversal of 261635040056 is 650040536162.

It is a happy number.

261635040056 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261635040053) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28908620 + ... + 28917668.

It is an arithmetic number, because the mean of its divisors is an integer number (8308510875).

Almost surely, 2^261635040056 is an apocalyptic number.

261635040056 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261635040056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265872348000).

261635040056 is an abundant number, since it is smaller than the sum of its proper divisors (270109655944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261635040056 is a wasteful number, since it uses less digits than its factorization.

261635040056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10848 (or 10844 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 38.

The spelling of 261635040056 in words is "two hundred sixty-one billion, six hundred thirty-five million, forty thousand, fifty-six".