261610265 has 12 divisors (see below), whose sum is σ = 365186916. Its totient is φ = 179389728.

The previous prime is 261610253. The next prime is 261610267. The reversal of 261610265 is 562016162.

It can be written as a sum of positive squares in 2 ways, for example, as 163916809 + 97693456 = 12803^2 + 9884^2 .

It is not a de Polignac number, because 261610265 - 2¹⁰ = 261609241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261610267) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 533654 + ... + 534143.

It is an arithmetic number, because the mean of its divisors is an integer number (30432243).

Almost surely, 2^261610265 is an apocalyptic number.

It is an amenable number.

261610265 is a deficient number, since it is larger than the sum of its proper divisors (103576651).

261610265 is a wasteful number, since it uses less digits than its factorization.

261610265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1067816 (or 1067809 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 261610265 is about 16174.3706214492. The cubic root of 261610265 is about 639.5653502237.

The spelling of 261610265 in words is "two hundred sixty-one million, six hundred ten thousand, two hundred sixty-five".