123205289 has 2 divisors, whose sum is σ = 123205290. Its totient is φ = 123205288.

The previous prime is 123205261. The next prime is 123205321. The reversal of 123205289 is 982502321.

It is a happy number.

It is an a-pointer prime, because the next prime (123205321) can be obtained adding 123205289 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82500889 + 40704400 = 9083^2 + 6380^2 .

It is a cyclic number.

It is not a de Polignac number, because 123205289 - 2²⁴ = 106428073 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (123205219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61602644 + 61602645.

It is an arithmetic number, because the mean of its divisors is an integer number (61602645).

Almost surely, 2^123205289 is an apocalyptic number.

It is an amenable number.

123205289 is a deficient number, since it is larger than the sum of its proper divisors (1).

123205289 is an equidigital number, since it uses as much as digits as its factorization.

123205289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 123205289 is about 11099.7877907643. The cubic root of 123205289 is about 497.5955073661.

The spelling of 123205289 in words is "one hundred twenty-three million, two hundred five thousand, two hundred eighty-nine".