206645 has 8 divisors (see below), whose sum is σ = 254904.
Its totient is φ = 160704.
The previous prime is 206641. The next prime is 206651. The reversal of 206645 is 546602.
It can be divided in two parts, 206 and 645, that multiplied together give a triangular number (132870 = T515).
206645 = T285 + T286 + ... +
It can be written as a sum of positive squares in 4 ways, for example, as 13924 + 192721 = 118^2 + 439^2
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 206645 - 22 = 206641 is a prime.
It is a Duffinian number.
It is a self number, because there is not a number n which added to its sum of digits gives 206645.
It is a congruent number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 206645.
It is not an unprimeable number, because it can be changed into a prime (206641) 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, 374 + ... + 743.
It is an arithmetic number, because the mean of its divisors is an integer number (31863).
2206645 is an apocalyptic number.
It is an amenable number.
206645 is a deficient number, since it is larger than the sum of its proper divisors (48259).
206645 is a wasteful number, since it uses less digits than its factorization.
206645 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1159.
The product of its (nonzero) digits is 1440, while the sum is 23.
The square root of 206645 is about 454.5822257854.
The cubic root of 206645 is about 59.1209812864.
The spelling of 206645 in words is "two hundred six thousand, six hundred forty-five".