65531 has 4 divisors (see below), whose sum is σ = 69000.
Its totient is φ = 62064.
The previous prime is 65521. The next prime is 65537. The reversal of 65531 is 13556.
It can be divided in two parts, 655 and 31, that added together give a palindrome (686).
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-65531 is a prime.
It is a super-2 number, since 2×655312 = 8588623922, which contains 22 as substring.
It is a Duffinian number.
It is a nialpdrome in base 10 and base 16.
It is not an unprimeable number, because it can be changed into a prime (65537) 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, 1706 + ... + 1743.
It is an arithmetic number, because the mean of its divisors is an integer number (17250).
65531 is a Friedman number, since it can be written as (5-3)^16-5, using all its digits and the basic arithmetic operations.
265531 is an apocalyptic number.
65531 is a deficient number, since it is larger than the sum of its proper divisors (3469).
65531 is a wasteful number, since it uses less digits than its factorization.
65531 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 3468.
The product of its digits is 450, while the sum is 20.
The square root of 65531 is about 255.9902341887.
The cubic root of 65531 is about 40.3164482442.
The spelling of 65531 in words is "sixty-five thousand, five hundred thirty-one".