123815854009 has 2 divisors, whose sum is σ = 123815854010. Its totient is φ = 123815854008.

The previous prime is 123815853983. The next prime is 123815854049. The reversal of 123815854009 is 900458518321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67390602409 + 56425251600 = 259597^2 + 237540^2 .

It is a cyclic number.

It is not a de Polignac number, because 123815854009 - 2¹¹ = 123815851961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123815854009.

It is not a weakly prime, because it can be changed into another prime (123815854049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61907927004 + 61907927005.

It is an arithmetic number, because the mean of its divisors is an integer number (61907927005).

Almost surely, 2^123815854009 is an apocalyptic number.

It is an amenable number.

123815854009 is a deficient number, since it is larger than the sum of its proper divisors (1).

123815854009 is an equidigital number, since it uses as much as digits as its factorization.

123815854009 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 46.

The spelling of 123815854009 in words is "one hundred twenty-three billion, eight hundred fifteen million, eight hundred fifty-four thousand, nine".