261805235328 has 384 divisors, whose sum is σ = 976035715200. Its totient is φ = 65412956160.

The previous prime is 261805235297. The next prime is 261805235333. The reversal of 261805235328 is 823532508162.

261805235328 is a `hidden beast` number, since 2 + 61 + 8 + 0 + 52 + 3 + 532 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

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, 1926088 + ... + 2057528.

It is an arithmetic number, because the mean of its divisors is an integer number (2541759675).

Almost surely, 2^261805235328 is an apocalyptic number.

261805235328 is a gapful number since it is divisible by the number (28) 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 261805235328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (488017857600).

261805235328 is an abundant number, since it is smaller than the sum of its proper divisors (714230479872).

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

261805235328 is a wasteful number, since it uses less digits than its factorization.

261805235328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131500 (or 131485 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 261805235328 in words is "two hundred sixty-one billion, eight hundred five million, two hundred thirty-five thousand, three hundred twenty-eight".