209188071 has 6 divisors (see below), whose sum is σ = 302160560. Its totient is φ = 139458708.

The previous prime is 209188051. The next prime is 209188073. The reversal of 209188071 is 170881902.

It is not a de Polignac number, because 209188071 - 2⁵ = 209188039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209188073) 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 5 ways as a sum of consecutive naturals, for example, 11621551 + ... + 11621568.

Almost surely, 2^209188071 is an apocalyptic number.

209188071 is a deficient number, since it is larger than the sum of its proper divisors (92972489).

209188071 is a wasteful number, since it uses less digits than its factorization.

209188071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23243125 (or 23243122 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 209188071 is about 14463.3354037027. The cubic root of 209188071 is about 593.6251673890.

The spelling of 209188071 in words is "two hundred nine million, one hundred eighty-eight thousand, seventy-one".