209553923 has 2 divisors, whose sum is σ = 209553924. Its totient is φ = 209553922.

The previous prime is 209553919. The next prime is 209553961. The reversal of 209553923 is 329355902.

It is an a-pointer prime, because the next prime (209553961) can be obtained adding 209553923 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209553923 - 2² = 209553919 is a prime.

It is not a weakly prime, because it can be changed into another prime (209553973) 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 as a sum of consecutive naturals, namely, 104776961 + 104776962.

It is an arithmetic number, because the mean of its divisors is an integer number (104776962).

Almost surely, 2^209553923 is an apocalyptic number.

209553923 is a deficient number, since it is larger than the sum of its proper divisors (1).

209553923 is an equidigital number, since it uses as much as digits as its factorization.

209553923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72900, while the sum is 38.

The square root of 209553923 is about 14475.9774454093. The cubic root of 209553923 is about 593.9710323443.

The spelling of 209553923 in words is "two hundred nine million, five hundred fifty-three thousand, nine hundred twenty-three".