206715505 has 4 divisors (see below), whose sum is σ = 248058612. Its totient is φ = 165372400.

The previous prime is 206715479. The next prime is 206715521. The reversal of 206715505 is 505517602.

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 103469584 + 103245921 = 10172^2 + 10161^2 .

It is not a de Polignac number, because 206715505 - 2⁵ = 206715473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20671546 + ... + 20671555.

It is an arithmetic number, because the mean of its divisors is an integer number (62014653).

Almost surely, 2^206715505 is an apocalyptic number.

It is an amenable number.

206715505 is a deficient number, since it is larger than the sum of its proper divisors (41343107).

206715505 is an equidigital number, since it uses as much as digits as its factorization.

206715505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41343106.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 206715505 is about 14377.6042858329. The cubic root of 206715505 is about 591.2770433125.

The spelling of 206715505 in words is "two hundred six million, seven hundred fifteen thousand, five hundred five".