12345678 has 24 divisors (see below), whose sum is σ = 27319968. Its totient is φ = 4027392.

The previous prime is 12345653. The next prime is 12345701. The reversal of 12345678 is 87654321.

12345678 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

12345678 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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

It is a Curzon number.

It is a straight-line number, since its digits are in arithmetic progression.

It is a plaindrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6451 + ... + 8142.

It is an arithmetic number, because the mean of its divisors is an integer number (1138332).

Almost surely, 2^12345678 is an apocalyptic number.

12345678 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12345678 is an abundant number, since it is smaller than the sum of its proper divisors (14974290).

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

12345678 is a wasteful number, since it uses less digits than its factorization.

12345678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14648 (or 14645 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 12345678 is about 3513.6417005722. The cubic root of 12345678 is about 231.1204184663.

Adding to 12345678 its reverse (87654321), we get a palindrome (99999999).

The spelling of 12345678 in words is "twelve million, three hundred forty-five thousand, six hundred seventy-eight".