261530541 has 12 divisors (see below), whose sum is σ = 387976732. Its totient is φ = 169641216.

The previous prime is 261530509. The next prime is 261530557. The reversal of 261530541 is 145035162.

261530541 is a `hidden beast` number, since 2 + 615 + 3 + 0 + 5 + 41 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 242424900 + 19105641 = 15570^2 + 4371^2 .

It is not a de Polignac number, because 261530541 - 2⁵ = 261530509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261530141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 392356 + ... + 393021.

Almost surely, 2^261530541 is an apocalyptic number.

It is an amenable number.

261530541 is a deficient number, since it is larger than the sum of its proper divisors (126446191).

261530541 is a wasteful number, since it uses less digits than its factorization.

261530541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785420 (or 785417 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 261530541 is about 16171.9059173618. The cubic root of 261530541 is about 639.5003758513.

The spelling of 261530541 in words is "two hundred sixty-one million, five hundred thirty thousand, five hundred forty-one".