206506156645 has 4 divisors (see below), whose sum is σ = 247807387980. Its totient is φ = 165204925312.

The previous prime is 206506156631. The next prime is 206506156693. The reversal of 206506156645 is 546651605602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 104770037124 + 101736119521 = 323682^2 + 318961^2 .

It is a cyclic number.

It is not a de Polignac number, because 206506156645 - 2²¹ = 206504059493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 206506156595 and 206506156604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20650615660 + ... + 20650615669.

It is an arithmetic number, because the mean of its divisors is an integer number (61951846995).

Almost surely, 2^206506156645 is an apocalyptic number.

It is an amenable number.

206506156645 is a deficient number, since it is larger than the sum of its proper divisors (41301231335).

206506156645 is an equidigital number, since it uses as much as digits as its factorization.

206506156645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41301231334.

The product of its (nonzero) digits is 1296000, while the sum is 46.

The spelling of 206506156645 in words is "two hundred six billion, five hundred six million, one hundred fifty-six thousand, six hundred forty-five".