206506621717 has 8 divisors (see below), whose sum is σ = 227510446752. Its totient is φ = 185874546000.

The previous prime is 206506621693. The next prime is 206506621751. The reversal of 206506621717 is 717126605602.

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

It is a de Polignac number, because none of the positive numbers 2^k-206506621717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206506624717) 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, 92936163 + ... + 92938384.

It is an arithmetic number, because the mean of its divisors is an integer number (28438805844).

Almost surely, 2^206506621717 is an apocalyptic number.

It is an amenable number.

206506621717 is a deficient number, since it is larger than the sum of its proper divisors (21003825035).

206506621717 is a wasteful number, since it uses less digits than its factorization.

206506621717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185874659.

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 206506621717 in words is "two hundred six billion, five hundred six million, six hundred twenty-one thousand, seven hundred seventeen".