123978908161 has 2 divisors, whose sum is σ = 123978908162. Its totient is φ = 123978908160.

The previous prime is 123978908101. The next prime is 123978908197. The reversal of 123978908161 is 161809879321.

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., 65454105600 + 58524802561 = 255840^2 + 241919^2 .

It is an emirp because it is prime and its reverse (161809879321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123978908161 - 2²¹ = 123976811009 is a prime.

It is not a weakly prime, because it can be changed into another prime (123978908101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61989454080 + 61989454081.

It is an arithmetic number, because the mean of its divisors is an integer number (61989454081).

Almost surely, 2^123978908161 is an apocalyptic number.

It is an amenable number.

123978908161 is a deficient number, since it is larger than the sum of its proper divisors (1).

123978908161 is an equidigital number, since it uses as much as digits as its factorization.

123978908161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1306368, while the sum is 55.

The spelling of 123978908161 in words is "one hundred twenty-three billion, nine hundred seventy-eight million, nine hundred eight thousand, one hundred sixty-one".