123201809 has 2 divisors, whose sum is σ = 123201810. Its totient is φ = 123201808.

The previous prime is 123201787. The next prime is 123201817. The reversal of 123201809 is 908102321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118875409 + 4326400 = 10903^2 + 2080^2 .

It is a cyclic number.

It is not a de Polignac number, because 123201809 - 2⁸ = 123201553 is a prime.

It is not a weakly prime, because it can be changed into another prime (123201829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61600904 + 61600905.

It is an arithmetic number, because the mean of its divisors is an integer number (61600905).

Almost surely, 2^123201809 is an apocalyptic number.

It is an amenable number.

123201809 is a deficient number, since it is larger than the sum of its proper divisors (1).

123201809 is an equidigital number, since it uses as much as digits as its factorization.

123201809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 123201809 is about 11099.6310299037. The cubic root of 123201809 is about 497.5908223706.

The spelling of 123201809 in words is "one hundred twenty-three million, two hundred one thousand, eight hundred nine".