261507560 has 32 divisors (see below), whose sum is σ = 589285800. Its totient is φ = 104444160.

The previous prime is 261507559. The next prime is 261507569. The reversal of 261507560 is 65705162.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 217444516 + 44063044 = 14746^2 + 6638^2 .

It is not an unprimeable number, because it can be changed into a prime (261507569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23750 + ... + 32970.

Almost surely, 2^261507560 is an apocalyptic number.

261507560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261507560 is an abundant number, since it is smaller than the sum of its proper divisors (327778240).

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

261507560 is a wasteful number, since it uses less digits than its factorization.

261507560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9941 (or 9937 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 261507560 is about 16171.1953794393. The cubic root of 261507560 is about 639.4816440828.

The spelling of 261507560 in words is "two hundred sixty-one million, five hundred seven thousand, five hundred sixty".