123078509 has 2 divisors, whose sum is σ = 123078510. Its totient is φ = 123078508.

The previous prime is 123078469. The next prime is 123078551. The reversal of 123078509 is 905870321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67158025 + 55920484 = 8195^2 + 7478^2 .

It is an emirp because it is prime and its reverse (905870321) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123078509 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123078209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61539254 + 61539255.

It is an arithmetic number, because the mean of its divisors is an integer number (61539255).

Almost surely, 2^123078509 is an apocalyptic number.

It is an amenable number.

123078509 is a deficient number, since it is larger than the sum of its proper divisors (1).

123078509 is an equidigital number, since it uses as much as digits as its factorization.

123078509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 123078509 is about 11094.0754008615. The cubic root of 123078509 is about 497.4247711641.

The spelling of 123078509 in words is "one hundred twenty-three million, seventy-eight thousand, five hundred nine".