12123456 has 56 divisors (see below), whose sum is σ = 32333184. Its totient is φ = 4008960.

The previous prime is 12123439. The next prime is 12123467. The reversal of 12123456 is 65432121.

12123456 = T₁₉₉ + T₂₀₀ + ... + T₄₃₁.

12123456 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

12123456 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44601 + ... + 44871.

Almost surely, 2^12123456 is an apocalyptic number.

12123456 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 12123456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16166592).

12123456 is an abundant number, since it is smaller than the sum of its proper divisors (20209728).

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

12123456 is a wasteful number, since it uses less digits than its factorization.

12123456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 509 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 12123456 is about 3481.8753567582. The cubic root of 12123456 is about 229.7252926938.

Adding to 12123456 its reverse (65432121), we get a palindrome (77555577).

The spelling of 12123456 in words is "twelve million, one hundred twenty-three thousand, four hundred fifty-six".