123775909 has 2 divisors, whose sum is σ = 123775910. Its totient is φ = 123775908.

The previous prime is 123775907. The next prime is 123775979. The reversal of 123775909 is 909577321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78818884 + 44957025 = 8878^2 + 6705^2 .

It is an emirp because it is prime and its reverse (909577321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123775909 - 2¹ = 123775907 is a prime.

Together with 123775907, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123775907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61887954 + 61887955.

It is an arithmetic number, because the mean of its divisors is an integer number (61887955).

Almost surely, 2^123775909 is an apocalyptic number.

It is an amenable number.

123775909 is a deficient number, since it is larger than the sum of its proper divisors (1).

123775909 is an equidigital number, since it uses as much as digits as its factorization.

123775909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 119070, while the sum is 43.

The square root of 123775909 is about 11125.4621926462. The cubic root of 123775909 is about 498.3625218515.

The spelling of 123775909 in words is "one hundred twenty-three million, seven hundred seventy-five thousand, nine hundred nine".