209045871 has 12 divisors (see below), whose sum is σ = 303538560. Its totient is φ = 138633120.

The previous prime is 209045867. The next prime is 209045897. The reversal of 209045871 is 178540902.

It is not a de Polignac number, because 209045871 - 2² = 209045867 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209045471) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 59086 + ... + 62523.

It is an arithmetic number, because the mean of its divisors is an integer number (25294880).

Almost surely, 2^209045871 is an apocalyptic number.

209045871 is a deficient number, since it is larger than the sum of its proper divisors (94492689).

209045871 is a wasteful number, since it uses less digits than its factorization.

209045871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121806 (or 121803 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 209045871 is about 14458.4186894695. The cubic root of 209045871 is about 593.4906271594.

It can be divided in two parts, 2090 and 45871, that added together give a square (47961 = 219²).

The spelling of 209045871 in words is "two hundred nine million, forty-five thousand, eight hundred seventy-one".