261273960 has 96 divisors (see below), whose sum is σ = 852382440. Its totient is φ = 69407232.

The previous prime is 261273953. The next prime is 261274001. The reversal of 261273960 is 69372162.

261273960 is a `hidden beast` number, since 2 + 612 + 7 + 39 + 6 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 252237924 + 9036036 = 15882^2 + 3006^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104242 + ... + 106718.

Almost surely, 2^261273960 is an apocalyptic number.

261273960 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 261273960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (426191220).

261273960 is an abundant number, since it is smaller than the sum of its proper divisors (591108480).

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

261273960 is a wasteful number, since it uses less digits than its factorization.

261273960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2787 (or 2780 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 261273960 is about 16163.9710467447. The cubic root of 261273960 is about 639.2911748736.

The spelling of 261273960 in words is "two hundred sixty-one million, two hundred seventy-three thousand, nine hundred sixty".