265244561 has 4 divisors (see below), whose sum is σ = 267591972. Its totient is φ = 262897152.

The previous prime is 265244519. The next prime is 265244563. The reversal of 265244561 is 165442562.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165442562 = 2 ⋅82721281.

It can be written as a sum of positive squares in 2 ways, for example, as 118374400 + 146870161 = 10880^2 + 12119^2 .

It is a cyclic number.

It is not a de Polignac number, because 265244561 - 2¹⁴ = 265228177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (265244563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1173536 + ... + 1173761.

It is an arithmetic number, because the mean of its divisors is an integer number (66897993).

Almost surely, 2^265244561 is an apocalyptic number.

It is an amenable number.

265244561 is a deficient number, since it is larger than the sum of its proper divisors (2347411).

265244561 is a wasteful number, since it uses less digits than its factorization.

265244561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2347410.

The product of its digits is 57600, while the sum is 35.

The square root of 265244561 is about 16286.3304952343. The cubic root of 265244561 is about 642.5133598034.

The spelling of 265244561 in words is "two hundred sixty-five million, two hundred forty-four thousand, five hundred sixty-one".