123978813 has 16 divisors (see below), whose sum is σ = 190793856. Its totient is φ = 70142400.

The previous prime is 123978769. The next prime is 123978817. The reversal of 123978813 is 318879321.

It is not a de Polignac number, because 123978813 - 2⁸ = 123978557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123978817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27106 + ... + 31347.

It is an arithmetic number, because the mean of its divisors is an integer number (11924616).

Almost surely, 2^123978813 is an apocalyptic number.

It is an amenable number.

123978813 is a deficient number, since it is larger than the sum of its proper divisors (66815043).

123978813 is a wasteful number, since it uses less digits than its factorization.

123978813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58564.

The product of its digits is 72576, while the sum is 42.

The square root of 123978813 is about 11134.5773606365. The cubic root of 123978813 is about 498.6346925981.

The spelling of 123978813 in words is "one hundred twenty-three million, nine hundred seventy-eight thousand, eight hundred thirteen".