261123560 has 16 divisors (see below), whose sum is σ = 587528100. Its totient is φ = 104449408.

The previous prime is 261123559. The next prime is 261123601. The reversal of 261123560 is 65321162.

It can be written as a sum of positive squares in 2 ways, for example, as 235499716 + 25623844 = 15346^2 + 5062^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3264005 + ... + 3264084.

Almost surely, 2^261123560 is an apocalyptic number.

261123560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261123560 is an abundant number, since it is smaller than the sum of its proper divisors (326404540).

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

261123560 is a wasteful number, since it uses less digits than its factorization.

261123560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6528100 (or 6528096 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 261123560 is about 16159.3180549180. The cubic root of 261123560 is about 639.1684839278.

The spelling of 261123560 in words is "two hundred sixty-one million, one hundred twenty-three thousand, five hundred sixty".