209130091 has 2 divisors, whose sum is σ = 209130092. Its totient is φ = 209130090.

The previous prime is 209130083. The next prime is 209130121. The reversal of 209130091 is 190031902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209130091 - 2³ = 209130083 is a prime.

It is not a weakly prime, because it can be changed into another prime (209130001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104565045 + 104565046.

It is an arithmetic number, because the mean of its divisors is an integer number (104565046).

Almost surely, 2^209130091 is an apocalyptic number.

209130091 is a deficient number, since it is larger than the sum of its proper divisors (1).

209130091 is an equidigital number, since it uses as much as digits as its factorization.

209130091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 209130091 is about 14461.3308861944. The cubic root of 209130091 is about 593.5703179140.

Adding to 209130091 its reverse (190031902), we get a palindrome (399161993).

The spelling of 209130091 in words is "two hundred nine million, one hundred thirty thousand, ninety-one".