206715091 has 4 divisors (see below), whose sum is σ = 225507384. Its totient is φ = 187922800.

The previous prime is 206715083. The next prime is 206715137. The reversal of 206715091 is 190517602.

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 206715091 - 2³ = 206715083 is a prime.

It is a super-2 number, since 2×206715091² = 85462257694276562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206715391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9396130 + ... + 9396151.

It is an arithmetic number, because the mean of its divisors is an integer number (56376846).

Almost surely, 2^206715091 is an apocalyptic number.

206715091 is a deficient number, since it is larger than the sum of its proper divisors (18792293).

206715091 is a wasteful number, since it uses less digits than its factorization.

206715091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18792292.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 206715091 is about 14377.5898884340. The cubic root of 206715091 is about 591.2766485850.

The spelling of 206715091 in words is "two hundred six million, seven hundred fifteen thousand, ninety-one".