12456789 has 8 divisors (see below), whose sum is σ = 16702560.
Its totient is φ = 8257776.
The previous prime is 12456751. The next prime is 12456791. The reversal of 12456789 is 98765421.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 12456789 - 217 = 12325717 is a prime.
It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.
It is a plaindrome in base 10.
It is a self number, because there is not a number n which added to its sum of digits gives 12456789.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (12456709) by changing a digit.
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 7 ways as a sum of consecutive naturals, for example, 11062 + ... + 12135.
It is an arithmetic number, because the mean of its divisors is an integer number (2087820).
Almost surely, 212456789 is an apocalyptic number.
It is an amenable number.
12456789 is a deficient number, since it is larger than the sum of its proper divisors (4245771).
12456789 is a wasteful number, since it uses less digits than its factorization.
12456789 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 23379.
The product of its digits is 120960, while the sum is 42.
The square root of 12456789 is about 3529.4176573480.
The cubic root of 12456789 is about 231.8117093436.
The spelling of 12456789 in words is "twelve million, four hundred fifty-six thousand, seven hundred eighty-nine".