206288391 has 4 divisors (see below), whose sum is σ = 275051192. Its totient is φ = 137525592.

The previous prime is 206288389. The next prime is 206288419. The reversal of 206288391 is 193882602.

It is a happy number.

206288391 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.

It is not a de Polignac number, because 206288391 - 2¹ = 206288389 is a prime.

It is a super-2 number, since 2×206288391² = 85109800522737762, which contains 22 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 (206288321) 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, 34381396 + ... + 34381401.

It is an arithmetic number, because the mean of its divisors is an integer number (68762798).

Almost surely, 2^206288391 is an apocalyptic number.

206288391 is a deficient number, since it is larger than the sum of its proper divisors (68762801).

206288391 is an equidigital number, since it uses as much as digits as its factorization.

206288391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68762800.

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 206288391 is about 14362.7431572106. The cubic root of 206288391 is about 590.8695318118.

The spelling of 206288391 in words is "two hundred six million, two hundred eighty-eight thousand, three hundred ninety-one".