206117691 has 16 divisors (see below), whose sum is σ = 296441376. Its totient is φ = 126637056.

The previous prime is 206117687. The next prime is 206117693. The reversal of 206117691 is 196711602.

206117691 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 206117691 - 2² = 206117687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (206117693) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22321 + ... + 30173.

It is an arithmetic number, because the mean of its divisors is an integer number (18527586).

Almost surely, 2^206117691 is an apocalyptic number.

206117691 is a deficient number, since it is larger than the sum of its proper divisors (90323685).

206117691 is a wasteful number, since it uses less digits than its factorization.

206117691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8542.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 206117691 is about 14356.7994692410. The cubic root of 206117691 is about 590.7065088035.

The spelling of 206117691 in words is "two hundred six million, one hundred seventeen thousand, six hundred ninety-one".