209798023 has 2 divisors, whose sum is σ = 209798024. Its totient is φ = 209798022.

The previous prime is 209798011. The next prime is 209798027. The reversal of 209798023 is 320897902.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209798023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209798027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104899011 + 104899012.

It is an arithmetic number, because the mean of its divisors is an integer number (104899012).

Almost surely, 2^209798023 is an apocalyptic number.

209798023 is a deficient number, since it is larger than the sum of its proper divisors (1).

209798023 is an equidigital number, since it uses as much as digits as its factorization.

209798023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 209798023 is about 14484.4062011530. The cubic root of 209798023 is about 594.2015729557.

The spelling of 209798023 in words is "two hundred nine million, seven hundred ninety-eight thousand, twenty-three".