206542145 has 4 divisors (see below), whose sum is σ = 247850580. Its totient is φ = 165233712.

The previous prime is 206542121. The next prime is 206542153. The reversal of 206542145 is 541245602.

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 78127921 + 128414224 = 8839^2 + 11332^2 .

It is a cyclic number.

It is not a de Polignac number, because 206542145 - 2⁶ = 206542081 is a prime.

It is a super-2 number, since 2×206542145² = 85319315322402050, which contains 22 as substring.

It is a Curzon 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, 20654210 + ... + 20654219.

It is an arithmetic number, because the mean of its divisors is an integer number (61962645).

Almost surely, 2^206542145 is an apocalyptic number.

It is an amenable number.

206542145 is a deficient number, since it is larger than the sum of its proper divisors (41308435).

206542145 is an equidigital number, since it uses as much as digits as its factorization.

206542145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41308434.

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 206542145 is about 14371.5742004834. The cubic root of 206542145 is about 591.1117074544. Note that the first 3 decimals are identical.

Adding to 206542145 its reverse (541245602), we get a palindrome (747787747).

The spelling of 206542145 in words is "two hundred six million, five hundred forty-two thousand, one hundred forty-five".