865123505 has 16 divisors (see below), whose sum is σ = 1094219280. Its totient is φ = 655619328.

The previous prime is 865123459. The next prime is 865123507. The reversal of 865123505 is 505321568.

865123505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 13184161 + 851939344 = 3631^2 + 29188^2 .

It is not a de Polignac number, because 865123505 - 2⁸ = 865123249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (865123507) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48602 + ... + 63971.

It is an arithmetic number, because the mean of its divisors is an integer number (68388705).

Almost surely, 2^865123505 is an apocalyptic number.

It is an amenable number.

865123505 is a deficient number, since it is larger than the sum of its proper divisors (229095775).

865123505 is a wasteful number, since it uses less digits than its factorization.

865123505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112660.

The product of its (nonzero) digits is 36000, while the sum is 35.

The square root of 865123505 is about 29412.9819127541. The cubic root of 865123505 is about 952.8532887127.

The spelling of 865123505 in words is "eight hundred sixty-five million, one hundred twenty-three thousand, five hundred five".