261709199136 has 648 divisors, whose sum is σ = 987605380944. Its totient is φ = 65000517120.

The previous prime is 261709199041. The next prime is 261709199149. The reversal of 261709199136 is 631991907162.

261709199136 is a `hidden beast` number, since 2 + 617 + 0 + 9 + 1 + 9 + 9 + 13 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 82116135 + ... + 82119321.

It is an arithmetic number, because the mean of its divisors is an integer number (1524082378).

Almost surely, 2^261709199136 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 261709199136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (493802690472).

261709199136 is an abundant number, since it is smaller than the sum of its proper divisors (725896181808).

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

261709199136 is a wasteful number, since it uses less digits than its factorization.

261709199136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3274 (or 3233 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The spelling of 261709199136 in words is "two hundred sixty-one billion, seven hundred nine million, one hundred ninety-nine thousand, one hundred thirty-six".