206560991 has 8 divisors (see below), whose sum is σ = 254229024. Its totient is φ = 163432800.

The previous prime is 206560987. The next prime is 206561009. The reversal of 206560991 is 199065602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 206560991 - 2² = 206560987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206560391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1134860 + ... + 1135041.

It is an arithmetic number, because the mean of its divisors is an integer number (31778628).

Almost surely, 2^206560991 is an apocalyptic number.

206560991 is a deficient number, since it is larger than the sum of its proper divisors (47668033).

206560991 is a wasteful number, since it uses less digits than its factorization.

206560991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2269921.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 206560991 is about 14372.2298548277. The cubic root of 206560991 is about 591.1296856293.

The spelling of 206560991 in words is "two hundred six million, five hundred sixty thousand, nine hundred ninety-one".