123565 has 8 divisors (see below), whose sum is σ = 159768. Its totient is φ = 91200.

The previous prime is 123553. The next prime is 123581. The reversal of 123565 is 565321.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1764 + 121801 = 42^2 + 349^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-123565 is a prime.

It is a Duffinian number.

123565 is a lucky number.

It is a nialpdrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 886 + ... + 1015.

It is an arithmetic number, because the mean of its divisors is an integer number (19971).

2¹²³⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

123565 is a deficient number, since it is larger than the sum of its proper divisors (36203).

123565 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 8 representation: 123565 = (361255)₈.

123565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919.

The product of its digits is 900, while the sum is 22.

The square root of 123565 is about 351.5181360897. The cubic root of 123565 is about 49.8079297921.

Adding to 123565 its reverse (565321), we get a palindrome (688886).

The spelling of 123565 in words is "one hundred twenty-three thousand, five hundred sixty-five".