209543145 has 16 divisors (see below), whose sum is σ = 383164800. Its totient is φ = 95791104.

The previous prime is 209543143. The next prime is 209543177. The reversal of 209543145 is 541345902.

It is not a de Polignac number, because 209543145 - 2¹ = 209543143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209543143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 997720 + ... + 997929.

It is an arithmetic number, because the mean of its divisors is an integer number (23947800).

Almost surely, 2^209543145 is an apocalyptic number.

It is an amenable number.

209543145 is a deficient number, since it is larger than the sum of its proper divisors (173621655).

209543145 is a wasteful number, since it uses less digits than its factorization.

209543145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995664.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 209543145 is about 14475.6051686967. The cubic root of 209543145 is about 593.9608489200.

The spelling of 209543145 in words is "two hundred nine million, five hundred forty-three thousand, one hundred forty-five".