206505001 has 4 divisors (see below), whose sum is σ = 218652372. Its totient is φ = 194357632.

The previous prime is 206504983. The next prime is 206505007. The reversal of 206505001 is 100505602.

It is a happy number.

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 129960000 + 76545001 = 11400^2 + 8749^2 .

It is a cyclic number.

It is not a de Polignac number, because 206505001 - 2⁷ = 206504873 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 206505001.

It is not an unprimeable number, because it can be changed into a prime (206505007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6073660 + ... + 6073693.

It is an arithmetic number, because the mean of its divisors is an integer number (54663093).

Almost surely, 2^206505001 is an apocalyptic number.

It is an amenable number.

206505001 is a deficient number, since it is larger than the sum of its proper divisors (12147371).

206505001 is a wasteful number, since it uses less digits than its factorization.

206505001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12147370.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 206505001 is about 14370.2818691910. The cubic root of 206505001 is about 591.0762706681.

It can be divided in two parts, 20650 and 5001, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 206505001 in words is "two hundred six million, five hundred five thousand, one".