123698909 has 2 divisors, whose sum is σ = 123698910. Its totient is φ = 123698908.

The previous prime is 123698867. The next prime is 123698921. The reversal of 123698909 is 909896321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123698884 + 25 = 11122^2 + 5^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123698909 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 (123698989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61849454 + 61849455.

It is an arithmetic number, because the mean of its divisors is an integer number (61849455).

Almost surely, 2^123698909 is an apocalyptic number.

It is an amenable number.

123698909 is a deficient number, since it is larger than the sum of its proper divisors (1).

123698909 is an equidigital number, since it uses as much as digits as its factorization.

123698909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 123698909 is about 11122.0011238985. The cubic root of 123698909 is about 498.2591579723.

The spelling of 123698909 in words is "one hundred twenty-three million, six hundred ninety-eight thousand, nine hundred nine".