261807305760 has 2592 divisors, whose sum is σ = 1308357925056. Its totient is φ = 48596889600.

The previous prime is 261807305759. The next prime is 261807305807. The reversal of 261807305760 is 67503708162.

261807305760 is a `hidden beast` number, since 2 + 6 + 1 + 8 + 0 + 73 + 0 + 576 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2592).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 8445396945 + ... + 8445396975.

It is an arithmetic number, because the mean of its divisors is an integer number (504767718).

Almost surely, 2^261807305760 is an apocalyptic number.

261807305760 is a gapful number since it is divisible by the number (20) 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 261807305760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (654178962528).

261807305760 is an abundant number, since it is smaller than the sum of its proper divisors (1046550619296).

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

261807305760 is a wasteful number, since it uses less digits than its factorization.

261807305760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 45.

The spelling of 261807305760 in words is "two hundred sixty-one billion, eight hundred seven million, three hundred five thousand, seven hundred sixty".