123123456 has 144 divisors (see below), whose sum is σ = 372825600. Its totient is φ = 40061952.

The previous prime is 123123397. The next prime is 123123461. The reversal of 123123456 is 654321321.

123123456 is a `hidden beast` number, since 1 + 2 + 312 + 345 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 324675 + ... + 325053.

Almost surely, 2^123123456 is an apocalyptic number.

123123456 is a gapful number since it is divisible by the number (16) 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 123123456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (186412800).

123123456 is an abundant number, since it is smaller than the sum of its proper divisors (249702144).

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

123123456 is an equidigital number, since it uses as much as digits as its factorization.

123123456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451 (or 431 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 123123456 is about 11096.1009368156. The cubic root of 123123456 is about 497.4853152572.

Adding to 123123456 its reverse (654321321), we get a palindrome (777444777).

The spelling of 123123456 in words is "one hundred twenty-three million, one hundred twenty-three thousand, four hundred fifty-six".