209983091 has 2 divisors, whose sum is σ = 209983092. Its totient is φ = 209983090.

The previous prime is 209983073. The next prime is 209983093. The reversal of 209983091 is 190389902.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209983091 is a prime.

Together with 209983093, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (209983093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104991545 + 104991546.

It is an arithmetic number, because the mean of its divisors is an integer number (104991546).

Almost surely, 2^209983091 is an apocalyptic number.

209983091 is a deficient number, since it is larger than the sum of its proper divisors (1).

209983091 is an equidigital number, since it uses as much as digits as its factorization.

209983091 is an evil number, because the sum of its binary digits is even.

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

The square root of 209983091 is about 14490.7933185178. The cubic root of 209983091 is about 594.3762415503.

The spelling of 209983091 in words is "two hundred nine million, nine hundred eighty-three thousand, ninety-one".