261041565 has 16 divisors (see below), whose sum is σ = 418385088. Its totient is φ = 138982656.

The previous prime is 261041533. The next prime is 261041591. The reversal of 261041565 is 565140162.

It is not a de Polignac number, because 261041565 - 2⁵ = 261041533 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5779 + ... + 23568.

It is an arithmetic number, because the mean of its divisors is an integer number (26149068).

Almost surely, 2^261041565 is an apocalyptic number.

It is an amenable number.

261041565 is a deficient number, since it is larger than the sum of its proper divisors (157343523).

261041565 is a wasteful number, since it uses less digits than its factorization.

261041565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29948.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 261041565 is about 16156.7807746469. The cubic root of 261041565 is about 639.1015754926.

The spelling of 261041565 in words is "two hundred sixty-one million, forty-one thousand, five hundred sixty-five".