206491 has 4 divisors (see below), whose sum is σ = 213184. Its totient is φ = 199800.

The previous prime is 206489. The next prime is 206501. The reversal of 206491 is 194602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194602 = 2 ⋅97301.

It is a cyclic number.

It is not a de Polignac number, because 206491 - 2¹ = 206489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206411) 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, 3300 + ... + 3361.

It is an arithmetic number, because the mean of its divisors is an integer number (53296).

2²⁰⁶⁴⁹¹ is an apocalyptic number.

206491 is a deficient number, since it is larger than the sum of its proper divisors (6693).

206491 is an equidigital number, since it uses as much as digits as its factorization.

206491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6692.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 206491 is about 454.4128079181. The cubic root of 206491 is about 59.1062912080.

The spelling of 206491 in words is "two hundred six thousand, four hundred ninety-one".