206153685950809 has 45 divisors (see below), whose sum is σ = 225027977312229. Its totient is φ = 188856065685960.

The previous prime is 206153685950767. The next prime is 206153685950833. The reversal of 206153685950809 is 908059586351602.

The square root of 206153685950809 is 14358053.

It is a perfect power (a square), and thus also a powerful number.

It is a de Polignac number, because none of the positive numbers 2^k-206153685950809 is a prime.

It is a super-2 number, since 2×206153685950809² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206153685950869) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 160680970482 + ... + 160680971764.

Almost surely, 2^{206153685950809} is an apocalyptic number.

206153685950809 is the 14358053-rd square number.

206153685950809 is the 7179027-th centered octagonal number.

It is an amenable number.

206153685950809 is a deficient number, since it is larger than the sum of its proper divisors (18874291361420).

206153685950809 is an frugal number, since it uses more digits than its factorization.

206153685950809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2704 (or 1333 counting only the distinct ones).

The product of its (nonzero) digits is 139968000, while the sum is 67.

The spelling of 206153685950809 in words is "two hundred six trillion, one hundred fifty-three billion, six hundred eighty-five million, nine hundred fifty thousand, eight hundred nine".