206731 has 6 divisors (see below), whose sum is σ = 240540. Its totient is φ = 177156.

The previous prime is 206699. The next prime is 206749. The reversal of 206731 is 137602.

It is not a de Polignac number, because 206731 - 2⁵ = 206699 is a prime.

It is a super-2 number, since 2×206731² = 85475412722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 206699 and 206708.

It is not an unprimeable number, because it can be changed into a prime (200731) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2061 + ... + 2158.

It is an arithmetic number, because the mean of its divisors is an integer number (40090).

2²⁰⁶⁷³¹ is an apocalyptic number.

206731 is a deficient number, since it is larger than the sum of its proper divisors (33809).

206731 is an equidigital number, since it uses as much as digits as its factorization.

206731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4233 (or 4226 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 206731 is about 454.6768082935. The cubic root of 206731 is about 59.1291816610.

The spelling of 206731 in words is "two hundred six thousand, seven hundred thirty-one".