261362770818912 has 288 divisors, whose sum is σ = 850331768832000. Its totient is φ = 74595745649664.

The previous prime is 261362770818871. The next prime is 261362770818977. The reversal of 261362770818912 is 219818077263162.

261362770818912 is a `hidden beast` number, since 2 + 613 + 6 + 2 + 7 + 7 + 0 + 8 + 1 + 8 + 9 + 1 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a self number, because there is not a number n which added to its sum of digits gives 261362770818912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11967696889 + ... + 11967718727.

It is an arithmetic number, because the mean of its divisors is an integer number (2952540864000).

Almost surely, 2^{261362770818912} 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 261362770818912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (425165884416000).

261362770818912 is an abundant number, since it is smaller than the sum of its proper divisors (588968998013088).

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

261362770818912 is a wasteful number, since it uses less digits than its factorization.

261362770818912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27898 (or 27887 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 63.

The spelling of 261362770818912 in words is "two hundred sixty-one trillion, three hundred sixty-two billion, seven hundred seventy million, eight hundred eighteen thousand, nine hundred twelve".