123671809 has 2 divisors, whose sum is σ = 123671810. Its totient is φ = 123671808.

The previous prime is 123671783. The next prime is 123671813. The reversal of 123671809 is 908176321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117245584 + 6426225 = 10828^2 + 2535^2 .

It is a cyclic number.

It is not a de Polignac number, because 123671809 - 2⁹ = 123671297 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123671309) 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, 61835904 + 61835905.

It is an arithmetic number, because the mean of its divisors is an integer number (61835905).

Almost surely, 2^123671809 is an apocalyptic number.

It is an amenable number.

123671809 is a deficient number, since it is larger than the sum of its proper divisors (1).

123671809 is an equidigital number, since it uses as much as digits as its factorization.

123671809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 123671809 is about 11120.7827512275. The cubic root of 123671809 is about 498.2227690516. Note that the first 3 decimals are identical.

The spelling of 123671809 in words is "one hundred twenty-three million, six hundred seventy-one thousand, eight hundred nine".