123815854109 has 2 divisors, whose sum is σ = 123815854110. Its totient is φ = 123815854108.

The previous prime is 123815854073. The next prime is 123815854133. The reversal of 123815854109 is 901458518321.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62805372100 + 61010482009 = 250610^2 + 247003^2 .

It is an emirp because it is prime and its reverse (901458518321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123815854109 - 2²⁸ = 123547418653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123815854159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61907927054 + 61907927055.

It is an arithmetic number, because the mean of its divisors is an integer number (61907927055).

Almost surely, 2^123815854109 is an apocalyptic number.

It is an amenable number.

123815854109 is a deficient number, since it is larger than the sum of its proper divisors (1).

123815854109 is an equidigital number, since it uses as much as digits as its factorization.

123815854109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 345600, while the sum is 47.

The spelling of 123815854109 in words is "one hundred twenty-three billion, eight hundred fifteen million, eight hundred fifty-four thousand, one hundred nine".