123401209 has 2 divisors, whose sum is σ = 123401210. Its totient is φ = 123401208.

The previous prime is 123401183. The next prime is 123401221. The reversal of 123401209 is 902104321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119421184 + 3980025 = 10928^2 + 1995^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123401209 is a prime.

It is a Chen prime.

It is equal to p_7024252 and since 123401209 and 7024252 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123401209.

It is not a weakly prime, because it can be changed into another prime (123401309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61700604 + 61700605.

It is an arithmetic number, because the mean of its divisors is an integer number (61700605).

Almost surely, 2^123401209 is an apocalyptic number.

It is an amenable number.

123401209 is a deficient number, since it is larger than the sum of its proper divisors (1).

123401209 is an equidigital number, since it uses as much as digits as its factorization.

123401209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 123401209 is about 11108.6096789832. The cubic root of 123401209 is about 497.8591250588.

The spelling of 123401209 in words is "one hundred twenty-three million, four hundred one thousand, two hundred nine".