209389091 has 8 divisors (see below), whose sum is σ = 216190464. Its totient is φ = 202668480.

The previous prime is 209389073. The next prime is 209389093. The reversal of 209389091 is 190983902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209389091 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209389093) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 14900 + ... + 25313.

It is an arithmetic number, because the mean of its divisors is an integer number (27023808).

Almost surely, 2^209389091 is an apocalyptic number.

209389091 is a deficient number, since it is larger than the sum of its proper divisors (6801373).

209389091 is a wasteful number, since it uses less digits than its factorization.

209389091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40381.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 209389091 is about 14470.2830310951. The cubic root of 209389091 is about 593.8152552324.

The spelling of 209389091 in words is "two hundred nine million, three hundred eighty-nine thousand, ninety-one".