240561 has 6 divisors (see below), whose sum is σ = 347490. Its totient is φ = 160368.

The previous prime is 240551. The next prime is 240571. The reversal of 240561 is 165042.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (240551) and next prime (240571).

It can be written as a sum of positive squares in only one way, i.e., 216225 + 24336 = 465^2 + 156^2 .

It is not a de Polignac number, because 240561 - 2⁷ = 240433 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (240551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13356 + ... + 13373.

It is an arithmetic number, because the mean of its divisors is an integer number (57915).

2²⁴⁰⁵⁶¹ is an apocalyptic number.

It is an amenable number.

240561 is a deficient number, since it is larger than the sum of its proper divisors (106929).

240561 is a wasteful number, since it uses less digits than its factorization.

240561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26735 (or 26732 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 240561 is about 490.4701825799. The cubic root of 240561 is about 62.1930334798.

The spelling of 240561 in words is "two hundred forty thousand, five hundred sixty-one".