261155093760 has 972 divisors, whose sum is σ = 1035339370884. Its totient is φ = 63063982080.

The previous prime is 261155093723. The next prime is 261155093761. The reversal of 261155093760 is 67390551162.

261155093760 is a `hidden beast` number, since 2 + 6 + 1 + 1 + 550 + 9 + 37 + 60 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 195307428096 + 65847665664 = 441936^2 + 256608^2 .

It is a tau number, because it is divible by the number of its divisors (972).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261155093761) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 1016167552 + ... + 1016167808.

Almost surely, 2^261155093760 is an apocalyptic number.

261155093760 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 261155093760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (517669685442).

261155093760 is an abundant number, since it is smaller than the sum of its proper divisors (774184277124).

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

261155093760 is an frugal number, since it uses more digits than its factorization.

261155093760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The spelling of 261155093760 in words is "two hundred sixty-one billion, one hundred fifty-five million, ninety-three thousand, seven hundred sixty".