123678517920 has 192 divisors, whose sum is σ = 424233936000. Its totient is φ = 30167617536.

The previous prime is 123678517909. The next prime is 123678517927. The reversal of 123678517920 is 29715876321.

It is a super-2 number, since 2×123678517920² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (123678517927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30666 + ... + 498294.

It is an arithmetic number, because the mean of its divisors is an integer number (2209551750).

Almost surely, 2^123678517920 is an apocalyptic number.

123678517920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123678517920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212116968000).

123678517920 is an abundant number, since it is smaller than the sum of its proper divisors (300555418080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123678517920 is a wasteful number, since it uses less digits than its factorization.

123678517920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 467695 (or 467687 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 51.

The spelling of 123678517920 in words is "one hundred twenty-three billion, six hundred seventy-eight million, five hundred seventeen thousand, nine hundred twenty".