261799615104 has 128 divisors (see below), whose sum is σ = 704154454080. Its totient is φ = 86175498240.

The previous prime is 261799615061. The next prime is 261799615111. The reversal of 261799615104 is 401516997162.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9813624 + ... + 9840264.

Almost surely, 2^261799615104 is an apocalyptic number.

261799615104 is a gapful number since it is divisible by the number (24) 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 261799615104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (352077227040).

261799615104 is an abundant number, since it is smaller than the sum of its proper divisors (442354838976).

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

261799615104 is a wasteful number, since it uses less digits than its factorization.

261799615104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26978 (or 26966 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 51.

The spelling of 261799615104 in words is "two hundred sixty-one billion, seven hundred ninety-nine million, six hundred fifteen thousand, one hundred four".