206266391 has 4 divisors (see below), whose sum is σ = 209092032. Its totient is φ = 203440752.

The previous prime is 206266381. The next prime is 206266397. The reversal of 206266391 is 193662602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 206266391 - 2¹⁸ = 206004247 is a prime.

It is a super-3 number, since 3×206266391³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206266397) 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, 1412711 + ... + 1412856.

It is an arithmetic number, because the mean of its divisors is an integer number (52273008).

Almost surely, 2^206266391 is an apocalyptic number.

206266391 is a deficient number, since it is larger than the sum of its proper divisors (2825641).

206266391 is an equidigital number, since it uses as much as digits as its factorization.

206266391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2825640.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 206266391 is about 14361.9772663794. The cubic root of 206266391 is about 590.8485262804.

The spelling of 206266391 in words is "two hundred six million, two hundred sixty-six thousand, three hundred ninety-one".