206531 has 4 divisors (see below), whose sum is σ = 222432. Its totient is φ = 190632.

The previous prime is 206527. The next prime is 206543. The reversal of 206531 is 135602.

206531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135602 = 2 ⋅67801.

It is not a de Polignac number, because 206531 - 2² = 206527 is a prime.

It is a super-2 number, since 2×206531² = 85310107922, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206501) 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, 7931 + ... + 7956.

It is an arithmetic number, because the mean of its divisors is an integer number (55608).

2²⁰⁶⁵³¹ is an apocalyptic number.

206531 is a deficient number, since it is larger than the sum of its proper divisors (15901).

206531 is a wasteful number, since it uses less digits than its factorization.

206531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15900.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 206531 is about 454.4568186308. The cubic root of 206531 is about 59.1101075147.

It can be divided in two parts, 206 and 531, that added together give a palindrome (737).

The spelling of 206531 in words is "two hundred six thousand, five hundred thirty-one".