123243209 has 2 divisors, whose sum is σ = 123243210. Its totient is φ = 123243208.

The previous prime is 123243191. The next prime is 123243229. The reversal of 123243209 is 902342321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119421184 + 3822025 = 10928^2 + 1955^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123243209 is a prime.

It is not a weakly prime, because it can be changed into another prime (123243229) 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, 61621604 + 61621605.

It is an arithmetic number, because the mean of its divisors is an integer number (61621605).

Almost surely, 2^123243209 is an apocalyptic number.

It is an amenable number.

123243209 is a deficient number, since it is larger than the sum of its proper divisors (1).

123243209 is an equidigital number, since it uses as much as digits as its factorization.

123243209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 123243209 is about 11101.4958001163. The cubic root of 123243209 is about 497.6465519446.

The spelling of 123243209 in words is "one hundred twenty-three million, two hundred forty-three thousand, two hundred nine".