261541365421116 has 576 divisors, whose sum is σ = 723952724060160. Its totient is φ = 72848954880000.

The previous prime is 261541365421087. The next prime is 261541365421157. The reversal of 261541365421116 is 611124563145162.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 52089494686 + ... + 52089499706.

It is an arithmetic number, because the mean of its divisors is an integer number (1256862368160).

Almost surely, 2^{261541365421116} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261541365421116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361976362030080).

261541365421116 is an abundant number, since it is smaller than the sum of its proper divisors (462411358639044).

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

261541365421116 is a wasteful number, since it uses less digits than its factorization.

261541365421116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5394 (or 5373 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 48.

The spelling of 261541365421116 in words is "two hundred sixty-one trillion, five hundred forty-one billion, three hundred sixty-five million, four hundred twenty-one thousand, one hundred sixteen".