It is a happy number.
3456789 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 straight-line number, since its digits are in arithmetic progression.
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 3456789.
It is a congruent number.
Almost surely, 23456789 is an apocalyptic number.
It is an amenable number.
3456789 is a wasteful number, since it uses less digits than its factorization.
3456789 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1804.
The square root of 3456789 is about 1859.2442012818. The cubic root of 3456789 is about 151.2020306410.
The spelling of 3456789 in words is "three million, four hundred fifty-six thousand, seven hundred eighty-nine".