209429091 has 8 divisors (see below), whose sum is σ = 310265360. Its totient is φ = 139619376.

The previous prime is 209429089. The next prime is 209429093. The reversal of 209429091 is 190924902.

It is an interprime number because it is at equal distance from previous prime (209429089) and next prime (209429093).

It is not a de Polignac number, because 209429091 - 2¹ = 209429089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209429093) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3878290 + ... + 3878343.

It is an arithmetic number, because the mean of its divisors is an integer number (38783170).

Almost surely, 2^209429091 is an apocalyptic number.

209429091 is a deficient number, since it is larger than the sum of its proper divisors (100836269).

209429091 is an equidigital number, since it uses as much as digits as its factorization.

209429091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7756642 (or 7756636 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 209429091 is about 14471.6651080655. The cubic root of 209429091 is about 593.8530653809.

The spelling of 209429091 in words is "two hundred nine million, four hundred twenty-nine thousand, ninety-one".